01966nas a2200241 4500008004100000020001800041022001400059245007800073210006900151260009500220300001200315490000600327520112400333653003001457653002501487653001901512653002201531100001601553700001801569700001601587700001301603856010801616 2005 eng d a90-6764-442-0 a1573-419600aDensity functional response approach for electric properties of molecules0 aDensity functional response approach for electric properties of  aCorinth, GreecebVsp BV-C/o Brill Acad Publ, Po Box 9000, 2300 Pa Leiden, NetherlandscOCT a142-1510 v33 a

We review in this paper an implementation of the response approach to the Kohn-Sham (KS) density functional theory (DFT) for obtaining the linear and non-linear electric response properties of molecules using Gaussian type orbital basis centered on atoms. We have made a formulation in which the response of the electron density through the solution of the coupled perturbed Kohn-Sham (CPKS) equations has to be obtained only once, instead of iteratively as in the case of completely analytic procedure. Our method is based on a numerical finite-field solution of derivative KS operator, followed by analytic solution of CPKS equation. Further, using the response of the electron density, the dipole moment, polarizability and first-hyperpolarizability of the molecules are evaluated. The method is particularly useful for large systems. We tested our method using HF, BH, H2O and CO as test molecules, for which, high quality ab initio results are available. Further, our study of possible incorporation of non-dynamical electron correlation by studying BH and HF at several internuclear distances is discussed.

10aDensity functional theory10amolecular properties10apolarizability10aResponse approach1 aPal, Sourav1 aSophy, K., B.1 aMaroulis, G1 aSimos, T uhttps://library.ncl.res.in/content/density-functional-response-approach-electric-properties-molecules-000654nas a2200169 4500008004100000020001800041022001400059245007000073210006900143260009500212300001400307490001000321100001600331700001400347700001700361856010600378 2005 eng d a90-6764-443-9 a1573-419600aReactivity descriptors: conceptual and computational developments0 aReactivity descriptors conceptual and computational developments aCorinth, GreecebVsp BV-C/o Brill Acad Publ, Po Box 9000, 2300 Pa Leiden, NetherlandscOCT a1172-11740 v4A-4B1 aPal, Sourav1 aSimos, T.1 aMaroulis, G. uhttps://library.ncl.res.in/content/reactivity-descriptors-conceptual-and-computational-developments-001348nas a2200217 4500008004100000022001400041245011300055210006900168260007300237300001200310490000800322520046700330653003200797653004600829653005400875653002000929100001600949700001500965700001800980856013200998 2006 eng d a0301-010400aAnalytically continued fock space multi-reference coupled-cluster theory: application to the shape resonance0 aAnalytically continued fock space multireference coupledcluster  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcOCT a283-2890 v3293 a

The Fock space multi-reference coupled-cluster (FSMRCC) method is used for the study of the shape resonance energy and width in an electron-atom/molecule collision. The procedure is based upon combining a complex absorbing potential (CAP) with FSMRCC theory. Accurate resonance parameters are obtained by solving a small non-Hermitian eigen-value problem. We study the shape resonances in e(-)-C2H4 and e(-)-Mg. (c) 2006 Elsevier B.V. All rights reserved.

10acomplex absorbing potential10acorrelated independent particle potential10aFock space multi-reference coupled-cluster theory10ashape resonance1 aPal, Sourav1 aSajeev, Y.1 aVaval, Nayana uhttps://library.ncl.res.in/content/analytically-continued-fock-space-multi-reference-coupled-cluster-theory-application-shape-001516nas a2200229 4500008004100000022001400041245011500055210006900170260007300239300001000312490000800322520066800330653002600998653002001024653001801044653002001062653001301082100002801095700001801123700001601141856012901157 2006 eng d a0166-128000aConstrained variational response to Fock-space multi-reference coupled-cluster theory: Some pilot applications0 aConstrained variational response to Fockspace multireference cou aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcAUG a91-960 v7683 a

Fock space (FS) multi-reference (MR) coupled-cluster (CC) has been established to be state-of-the-art method for energies of open-shell radicals, ionized, electron attached states and excited states. Due to the multi-root nature of the method, the linear response of MRCC, however, is non-trivial. Constrained variation approach (CVA) makes it plausible to calculate response of the MRCC method efficiently. However, the approach is used for only one root of the problem at a time. In the present article, we make first implementation of the approach and present test results of dipole moments of small radicals. (c) 2006 Elsevier B.V. All rights reserved.

10aconstrained variation10acoupled-cluster10aDipole moment10aMulti-reference10aresponse1 aManohar, Prashant, Uday1 aVaval, Nayana1 aPal, Sourav uhttps://library.ncl.res.in/content/constrained-variational-response-fock-space-multi-reference-coupled-cluster-theory-some-001276nas a2200169 4500008004100000022001400041245014400055210006900199260012500268300002300393490000800416520050200424100002100926700001800947700001600965856012500981 2006 eng d a0021-960600aInteraction induced shifts in O-H stretching frequency of water in halide-ion water clusters: a microscopic approach with a bond descriptor0 aInteraction induced shifts in OH stretching frequency of water i aCIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USAbAMER INST PHYSICScDEC aArticle No. 2143040 v1253 a

Based on conceptual density functional theory, two new descriptors, the normalized atom-condensed Fukui functions (NFFs) and bond deformation kernel (BDK), are proposed to describe the O-H stretching frequency shifts in water halide-ion clusters by including local polarizations in the system. NFF, along with BDK, can be successfully used to describe interactions between different atoms, especially in cases where polarizations are quite important. (c) 2006 American Institute of Physics.

1 aTanwar, Akhilesh1 aBagchi, Biman1 aPal, Sourav uhttps://library.ncl.res.in/content/interaction-induced-shifts-o-h-stretching-frequency-water-halide-ion-water-clusters-100623nas a2200169 4500008004100000022001400041245003800055210003800093260012600131300002300257490000800280100002100288700001600309700002400325700002900349856007500378 2006 eng d a0021-960600aMinimum magnetizability principle0 aMinimum magnetizability principle aCIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USAbAMER INST PHYSICScAUG  aArticle No. 0561010 v1251 aTanwar, Akhilesh1 aPal, Sourav1 aRoy, Debesh, Ranjan1 aChattaraj, Pratim, Kumar uhttps://library.ncl.res.in/content/minimum-magnetizability-principle-101566nas a2200253 4500008004100000022001400041245006300055210006200118260007700180300001400257490000600271520075100277653003601028653000901064653002001073653002401093653001301117100001801130700002001148700001701168700002001185700001601205856009101221 2006 eng d a1439-423500aTheoretical study of N2O reduction by CO in Fe-BEA zeolite0 aTheoretical study of N2O reduction by CO in FeBEA zeolite aPO BOX 10 11 61, D-69451 WEINHEIM, GERMANYbWILEY-V C H VERLAG GMBHcAUG a1795-18010 v73 a

Quantum mechanical (QM) and QM/molecular mechanics (MM) studies of the full catalytic cycle of N2O reduction by CO in Fe-BEA zeolite, that is, oxidation of BEA-Fe by NO and reduction of BEA-Fe-alpha O by CO, is presented. A large QM cluster, representing half of the channel of the BEA zeolite, is used. The contribution of the MM embedding to the calculated activation energies is found to be negligible. The minimum-energy paths for N2O decomposition and reduction with CO are calculated using the nudged elastic bond (NEB) method. Calculated band experimental activation energies ore in good agreement The two possible orientations for the gaseous molecules adsorbing on the Fe site that ore found lead to different activation energies.

10aDensity functional calculations10airon10anitrogen oxides10areaction mechanisms10azeolites1 aFischer, Gerd1 aGoursot, Annick1 aCoq, Bernard1 aDelahay, Gerard1 aPal, Sourav uhttps://library.ncl.res.in/content/theoretical-study-n2o-reduction-co-fe-bea-zeolite-001838nas a2200253 4500008004100000020002200041022001400063245018300077210006900260260016600329300001200495490000800507520079600515653000801311653001801319653001901337653001101356653001901367100002801386700001601414700001601430700001401446856012401460 2007 eng d a978-0-7354-0477-9 a0094-243X00aConstrained variational response to fock-space multi-reference coupled-cluster theory: formulation for excited-state electronic structure calculations and some pilot applications0 aConstrained variational response to fockspace multireference cou a2 Huntington Quadrangle, Ste 1no1, Melville, NY 11747-4501 USAbEuropean Soc Computat Methods Sci & Engn; Minist Natl Educ & Religious Affairs; E4 Comp EngncSEP a337-3440 v9633 a

Fock-space (FS) multi-reference (MR) coupled-cluster (CC) method has emerged as compact tool to account for electronic structure of open-shell systems and molecules in low-lying excited states. Development of linear response (LR) has been one of the challenging problems in FSMRCC due to multiple-root nature of effective Hamiltonian. The recently developed constrained variational approach (CVA) has opened up a promising tool for efficient evaluation of analytic response properties. In this article, we present formulation of the method for excited state calculations. We discuss the decoupling of equations as a result of spin-adaptation and present some preliminary results for analytical dipole moments and polarizabilities of some molecules in low-lying triplet excited states.

10aCVA10aDipole moment10aexcited states10aFSMRCC10apolarizability1 aManohar, Prashant, Uday1 aPal, Sourav1 aMaroulis, G1 aSimos, TE uhttps://library.ncl.res.in/content/constrained-variational-response-fock-space-multi-reference-coupled-cluster-theory-000892nas a2200169 4500008004100000022001400041245020100055210006900256260007100325300001200396490000600408520011900414100001800533700002500551700001600576856013000592 2007 eng d a1549-961800aDensity functional static dipole polarizability and first-hyperpolarizability calculations of Na-n (n=2, 4, 6, 8) clusters using an approximate CPKS method and its comparison with MP2 calculations0 aDensity functional static dipole polarizability and firsthyperpo a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcMAY a716-7270 v33 a

{We report the static dipole polarizability and first-hyperpolarizability of the sodium atom clusters, Na-n

1 aSophy, K., B.1 aCalaminici, Patrizia1 aPal, Sourav uhttps://library.ncl.res.in/content/density-functional-static-dipole-polarizability-and-first-hyperpolarizability-calculations01693nas a2200193 4500008004100000022001400041245009600055210006900151260007100220300001400291490000800305520097000313100001901283700001601302700002101318700002101339700001601360856012301376 2007 eng d a1089-563900aDeprotonation of 1,2-dialkylpyridinium ions: a DFT study of reactivity and site selectivity0 aDeprotonation of 12dialkylpyridinium ions a DFT study of reactiv a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcSEP a8823-88280 v1113 a

A site-selectivity model, based on the Fukui function as a local reactivity descriptor, has been applied to 1.2-disubstituted pyridinium ions incorporating two competing sites of similar reactivity, i.e., 1-methylene and 2-methylene, which may undergo deprotonation depending on the nature of substituent present on these moieties. Applicability of the local HSAB rule, in context with the Li-Evans' generalized HSAB principle suggesting the hard-hard interactions to be controlled by minimum Fukui function, has been illustrated. Global and local reactivity descriptors have been computed by carrying out DFT calculations at B3LYP/6-31++G** level using Mulliken and NPA methods for charge analysis. A comparison with the calculated deprotonation energies involving two sites indicates that the observed site selectivity in differently substituted pyridinium ions is better explained by the Li-Evans rule of minimum Fukui function for hard-hard interactions.

1 aGupta, Neelima1 aGarg, Reena1 aShah, Kirti, Kr.1 aTanwar, Akhilesh1 aPal, Sourav uhttps://library.ncl.res.in/content/deprotonation-12-dialkylpyridinium-ions-dft-study-reactivity-and-site-selectivity-001343nas a2200157 4500008004100000022001400041245015500055210006900210260007300279300001200352490000800364520064400372100002801016700001601044856012501060 2007 eng d a0009-261400aDipole moments and polarizabilities of some small radicals using constrained variational response to fock-space multi-reference coupled-cluster theory0 aDipole moments and polarizabilities of some small radicals using aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcAPR a321-3250 v4383 a

In this Letter, we present dipole moments and polarizabilities of some open-shell doublet radicals, obtained analytically using constrained variational response to Fock-space (FS) multi-reference (MR) coupled cluster (CC) theory. These radicals can be treated as electron attached (EA) states of the corresponding closed-shell cations. Additionally, we also report analytical polarizabilities of some doublet radicals, which can be considered as ionized (IP) states of the corresponding anions. We compare our results with finite field FSMRCC response and the available benchmark results. (c) 2007 Elsevier B.V. All rights reserved.

1 aManohar, Prashant, Uday1 aPal, Sourav uhttps://library.ncl.res.in/content/dipole-moments-and-polarizabilities-some-small-radicals-using-constrained-variational01408nas a2200181 4500008004100000022001400041245008000055210006900135260012500204300001100329490000800340520068800348100001801036700001601054700001901070700002301089856011401112 2007 eng d a0021-960600aElectronic structure of spherical quantum dots using coupled cluster method0 aElectronic structure of spherical quantum dots using coupled clu aCIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USAbAMER INST PHYSICScSEP a1147080 v1273 a

2, 6, 12, and 20 electron quantum dots have been studied using coupled cluster at singles and doubles level and extensive multireference coupled cluster (MRCC) method. A Fock-space version of MRCC (FSMRCC) containing single hole-particle excited determinants has been used to calculate low-lying excited states of the above system. The ionization potential and electron affinity are also calculated. The effect of correlation energy on excitation energy and charge density is shown by calculating them at the high density region (low value of density parameter r(s)) and at the low density region (high value of density parameter r(s)). (c) 2007 American Institute of Physics.

1 aHeidari, Ideh1 aPal, Sourav1 aPujari, B., S.1 aKanhere, Dilip, G. uhttps://library.ncl.res.in/content/electronic-structure-spherical-quantum-dots-using-coupled-cluster-method-001694nas a2200169 4500008004100000022001400041245013200055210006900187260007100256300001200327490000800339520098900347100001501336700002801351700001601379856012901395 2007 eng d a1089-563900aInfluence of electric field on the global and local reactivity descriptors: reactivity and stability of weakly bonded complexes0 aInfluence of electric field on the global and local reactivity d a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcJAN a375-3830 v1113 a

The response of the global and local reactivity density-based descriptors (chemical potential, hardness, softness, Fukui function, and local softness) in the presence of external electric field has been studied for some of the simple prototype molecular systems. In addition to the analysis on the reactivity of these systems, the influence of the electric field on the interaction energy of the complexes formed by these systems has also been studied using the recently proposed semiquantitative model based on the local hard-soft acid-base principle. By using the inverse relationship between the global hardness and softness parameters, a simple relationship is obtained for the variation of hardness in terms of the Fukui function under the external electric field. It is shown that the increase in the hardness values for a particular system in the presence of external field does not necessarily imply that the reactivity of the system would be deactivated or vice versa.

1 aKar, Rahul1 aChandrakumar, K., R. S.1 aPal, Sourav uhttps://library.ncl.res.in/content/influence-electric-field-global-and-local-reactivity-descriptors-reactivity-and-stability01025nas a2200193 4500008004100000022001400041245008100055210006900136260009400205300001400299490000700313520027800320653003300598653003600631100001600667700001800683700001500701856011500716 2007 eng d a0973-145800aShape resonance in electron molecule scattering using coupled cluster method0 aShape resonance in electron molecule scattering using coupled cl aINDIAN J PHYSICS, JADAVPUR, KOLKATA 700 032, INDIAbINDIAN ASSOC CULTIVATION SCIENCEcOCT a1061-10670 v813 a

The Fock space multi-reference coupled-cluster (FSMRCC) method along with the complex absorbing potential (CAP) is used for the study of the shape resonance energy and width in an electron molecule collision. We study the shape resonances in e(-) -H2CO and e(-) -CO.

10aelectron-molecule scattering10amulti-reference coupled-cluster1 aPal, Sourav1 aVaval, Nayana1 aSajeev, Y. uhttps://library.ncl.res.in/content/shape-resonance-electron-molecule-scattering-using-coupled-cluster-method-001331nas a2200169 4500008004100000022001400041245014200055210006900197260012500266300001100391490000800402520057200410100001900982700001601001700001801017856012601035 2008 eng d a0021-960600aCalculation of vibrational energy of molecule using coupled cluster linear response theory in bosonic representation: convergence studies0 aCalculation of vibrational energy of molecule using coupled clus aCIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USAbAMER INST PHYSICScOCT a1341110 v1293 a

Vibrational excited state energies have been calculated using vibrational coupled cluster linear response theory (CCLRT). The method has been implemented on formaldehyde and water molecule. Convergence studies have been shown with varying the cluster operator from S(4) to S(6) as well as the excitation operator from four bosons to six bosons. A good agreement with full configuration interaction results has been observed with S(6) truncation at coupled-cluster method level and six bosonic excitations at CCLRT level. (C) 2008 American Institute of Physics.

1 aBanik, Subrata1 aPal, Sourav1 aPrasad, Durga uhttps://library.ncl.res.in/content/calculation-vibrational-energy-molecule-using-coupled-cluster-linear-response-theory-001640nas a2200193 4500008004100000022001400041245013400055210006900189260007100258300001400329490000800343520086800351100001901219700002501238700002301263700002001286700001601306856012401322 2008 eng d a1520-610600aComparative study of structural, acidic and hydrophilic properties of Sn-BEA with Ti-BEA using periodic density functional theory0 aComparative study of structural acidic and hydrophilic propertie a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcMAR a2573-25790 v1123 a

Periodic density functional theory has been employed to characterize the differences in the structural, Lewis acidic and hydrophilic properties of Sn-BEA and Ti-BEA. We show that the incorporation of Sri increases the Lewis acidity of BEA compared to the incorporation of Ti. Hence, the present work gives insight into the role of Sn in increasing the efficiency of the oxidation reactions. The results also justify that the percentage of Sri substituted in BEA is less than Ti. The structural analysis shows that the first coordination shell of Sri is larger than that of Ti. However, the second coordination of both sites remains the same. The water adsorption properties of these substituted zeolites are quantified. Moreover, we explain the higher Lewis acidity of Sn than the Ti site on the basis of the Fukui functions and charge population analysis.

1 aShetty, Sharan1 aKulkarni, Bhakti, S.1 aKanhere, Dilip, G.1 aGoursot, Annick1 aPal, Sourav uhttps://library.ncl.res.in/content/comparative-study-structural-acidic-and-hydrophilic-properties-sn-bea-ti-bea-using-002127nas a2200229 4500008004100000022001400041245013700055210006900192260007700261300001200338490000600350520124500356653001901601653003601620653001301656653002101669653001901690100001901709700001601728700002301744856013001767 2008 eng d a1439-423500aDensity functional investigations of electronics structure and dehydrogenation reactions of Al- and Si-substituted magnesium hydride0 aDensity functional investigations of electronics structure and d aPO BOX 10 11 61, D-69451 WEINHEIM, GERMANYbWILEY-V C H VERLAG GMBHcAPR a928-9340 v93 a

{The effect on the hydrogen storage attributes of magnesium hydride (MgH2) of the substitution of Mg by varying fractions of Al and Si is investigated by an ab initio plane-wave pseuodopotential method based on density functional theory. Three supercells, namely, 2 x 2 x x 3 x 1 x 1 and 5 x 1 x 1 are used for generating configurations with varying amounts (fractions x=0.0625, 0.1, and 0.167) of impurities. The analyses of band structure and density of states (DOS) show that, when a Mg atom is replaced by Al, the band gap vanishes as the extra electron occupies the conduction band minimum. In the case of Si-substitution, additional states are generated within the band gap of pure MgH2-significontly reducing the gap in the process. The reduced band gaps cause the Mg-H bond to become more susceptible to dissociation. For all the fractions, the calculated reaction energies for the stepwise removal of H-2 molecules from Al- and Si-substituted MgH2 ore much lower than for H-2 removal from pure MgH2. The reduced stability is also reflected in the comparatively smaller heats of formation (Delta H-f) of the substituted MgH2 systems. Si causes greater destabilization of MgH2 than Al for each x. For fractions x = 0.167 of Al

10aband structure10aDensity functional calculations10ahydrides10aHydrogen storage10aThermodynamics1 aKelkar, Tuhina1 aPal, Sourav1 aKanhere, Dilip, G. uhttps://library.ncl.res.in/content/density-functional-investigations-electronics-structure-and-dehydrogenation-reactions-al-001418nas a2200205 4500008004100000022001400041245007800055210006900133260005700202300001200259490000800271520067900279653001900958653002600977653004201003653002701045100001501072700001601087856010901103 2008 eng d a1432-881X00aElectric field response of molecular reactivity descriptors: a case study0 aElectric field response of molecular reactivity descriptors a ca a233 SPRING ST, NEW YORK, NY 10013 USAbSPRINGERcJUL a375-3830 v1203 a

In the present article, we study the influence of external electric field on the density-based global and local reactivity descriptors using examples of some planar nonlinear polyatomic molecules with C-2V point group symmetry. The study mainly involves the application of weak electric field in a direction along the principal axis and along its perpendicular direction. We also discuss the strength of the electric field studied in this work in terms of the strength of the molecular interaction. The work is expected to throw light on the effect of interactions within the above range on reactivity descriptors. Results are presented for a few prototype molecules.

10aelectric field10amolecular interaction10aplanar nonlinear polyatomic molecules10aReactivity descriptors1 aKar, Rahul1 aPal, Sourav uhttps://library.ncl.res.in/content/electric-field-response-molecular-reactivity-descriptors-case-study-002881nas a2200229 4500008004100000022001400041245012700055210006900182260007300251300001200324490000700336520200400343653002202347653002102369653002102390653002202411653002902433100001902462700002302481700001602504856013102520 2008 eng d a0927-025600aFirst principles calculations of thermal, equations of state and thermodynamical properties of MgH2 at finite temperatures0 aFirst principles calculations of thermal equations of state and  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcMAY a510-5160 v423 a

We present the first principles calculations of the thermodynamical properties of magnesium hydride (MgH2) over a temperature range of 0-1000 K. The phonon dispersions are determined within the density functional framework and are used to calculate the free energy of MgH2 within the quasiharmonic approximation (QHA) at each cell volume and temperature T. Using the free energies the thermal equation of state (EOS) is derived at several temperatures. From the thermal EOS structural parameters such as the equilibrium bell volume (V-0) and elastic properties, namely, bulk modulus (K-0) and its pressure derivative (K-0(')) are computed. The free energies are also used to calculate various thermodynamical properties within QHA. These include internal energy E, entropy S, specific heat capacity at constant pressure C-P, thermal pressure P-thermal(V,T) and volume thermal expansion Delta V/V (%). The good agreement of calculated values of S and Cp with experimental data exhibits that QHA can be used as a tool for calculating the thermodynamical properties of MgH2 over a wide temperature range. P-thermal(V,T) increases strongly with T at all the volumes but it is a slowly varying function of volume for T = 298-500 K. According to Karki [B.B. Karki, Am. Miner. 85 (2000) 1447] such volume based variations can be neglected and so it is possible to estimate the thermal EOS only with the knowledge of the measured P-thermal(V,T) versus temperature at ambient pressure and isothermal compression data at ambient temperature. Temperature dependence of Delta V/V(%) shows that V-0 increased with increase in temperature. However, the percentage decrease in K-0 superseded this percentage increase in V-0 even at temperatures moderately higher than 298 K. Therefore, we suggest application of temperature (T > 298 K) as an approach to enhance the hydrogen storage capacity of MgH2 because of its better compressibility at these temperatures. (C) 2007 Elsevier B.V. All rights reserved.

10aequation of state10aHydrogen storage10alattice dynamics10amagnesium hydride10aThermodynamic properties1 aKelkar, Tuhina1 aKanhere, Dilip, G.1 aPal, Sourav uhttps://library.ncl.res.in/content/first-principles-calculations-thermal-equations-state-and-thermodynamical-properties-mgh2-001575nas a2200169 4500008004100000022001400041245015600055210006900211260007100280300001600351490000800367520084100375100001801216700002301234700001601257856013201273 2008 eng d a1089-563900aNoniterative density functional response approach: application to nonlinear optical properties of p-nitroaniline and its methyl-substituted derivatives0 aNoniterative density functional response approach application to a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcNOV a11266-112720 v1123 a

We report the effect of substitution, position of the substituent, and the symmetry on the nonlinear optical properties of p-nitroanline (PNA) and its derivatives using our implementation of the noniterative approximation of couple-perturbed Kohn-Sham (CPKS) equation in the deMon2k. Dipole moment, static polarizability, and first hyperpolarizability of these pi-conjugated donor-acceptor organic derivatives of PNA and its methyl-substituted analogs are calculated using our method at different exchange correlation functionals, namely, BP86, BPW91, and BLYP, using 6-31++G** basis set. A comparison of results obtained by our method with those obtained by MP2 (finite-field perturbation) method is presented in this paper. The effect of optical gap on charge transfer and subsequently on polarizabilities has been illustrated.

1 aSophy, K., B.1 aShedge, Sapana, V.1 aPal, Sourav uhttps://library.ncl.res.in/content/noniterative-density-functional-response-approach-application-nonlinear-optical-properties-002759nas a2200229 4500008004100000022001400041245008300055210006900138260007300207300000800280490000800288520196600296653001002262653001602272653002402288653000802312653002202320100002702342700002502369700001602394856011902410 2009 eng d a0022-286000aBond length variations: electron number profiles and transferable atomic sizes0 aBond length variations electron number profiles and transferable aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcNOV a1-80 v9363 a

A profile of the number of electrons with distance along the M-X bond in gas-phase diatomic molecules has been obtained from electron density plots calculated using DFT B3LYP 6-311G** method for some representative molecules. This ``number profile'' is compared with that expected from the partitioning of the 1D bond-distance into atom-specific transferable ``hub'' or core atomic sizes of the M and X atoms and another ``axle'' size which is associated with a pair of (bonding) electrons. The ``hub'' size is proportional to a core atom-specific size, r(nZ)(c) with r(nZ)(c)(M) >= r(nZ)(c)(X). For ``single bonds'', the ``hub'' size for M atom is C(M)r(nZ)(c)(M) and for X atom is C(X)r(nZ)(c)(X). The ``axle'' size, DMX, is usually the ordinary (similar to 4a(H)/3 where a(H) is the Bohr radius of the hydrogen atom) or elongated (similar to 2a(H)) bond length of the hydrogen molecule. The ``hub'' and ``axle'' sizes could be characterized ``charge-transfer'' (C(M) = pi(2/3) = 2.144; C(X) = pi(4/3)/2 = 2.300 and D(MX) = 4a(H)/3) or ``neutral'' (CM or C(X) = 1, 2, ... and D(MX) = 2a(H)). We use a new ``static'' or ``peripatetic'' classification for the core sizes which is derived from a new condition for metallization in elements based on atomic size. The charge-transfer distance, d(MX)(+/-), is usually found for ``static'' conditions while the ``neutral'' description is usually found when X = F or for ``peripatetic'' conditions. Such a partitioning is seen to agree with that from the plot of the total number of electrons, N(el), vs r along a bond axis. The Nel vs r plots from each atom are described by a simple hydrogen-atom-like function which differ away (''out'') or towards (''in'') the M-X bond. Thus N(in,out)(M, X) = (Z(M,X) +/- 1) exp (-r/B(in,out)) where the minus sign is associated with M and plus sign with X and Bin, out being related inversely to the Slater orbital exponent. (C) 2009 Elsevier B.V. All rights reserved.

10aB3LYP10aBond length10aBond-stretch isomer10aDFT10aDiatomic molecule1 aGanguly, Parthasarathy1 aKulkarni, Bhakti, S.1 aPal, Sourav uhttps://library.ncl.res.in/content/bond-length-variations-electron-number-profiles-and-transferable-atomic-sizes-002112nas a2200157 4500008004100000022001400041245015200055210006900207260011000276300001400386490000700400520138200407100001901789700001601808856013001824 2009 eng d a0959-942800aComputational study of electronic structure, thermodynamics and kinetics of hydrogen desorption from Al- and Si-doped alpha-, gamma-, and beta-MgH20 aComputational study of electronic structure thermodynamics and k aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcAPR a4348-43550 v193 a

First principles calculations of pure and Al-and Si-doped alpha-, gamma-, and beta-MgH2 were performed to investigate the influence of Al and Si as impurities and the presence of high pressure phases on the properties of hydrogen sorption of magnesium hydride. The ab initio plane wave pseudopotential method based on density functional theory within the generalized gradient approximation was used in the present study. The total energies of the considered systems were calculated as a function of cell volume to obtain material properties such as bulk modulus K-0, equilibrium cell volume V-0 and minimum energy E-0(V-0). From the density of states (DOS) analysis, it was shown that doping MgH2 with Al and Si caused a reduction in the band gaps of each of the three phases. The diminished band gaps made the Mg-H bond more susceptible to dissociation. The destabilization of the hydrides was reflected in the decreased heats of formation of the doped hydrides, with the following Delta H-f order: Si < Al and beta < gamma < alpha. A 30.5% reduction in the activation energy barrier E-act for H-2 desorption was calculated for the Al-doped alpha-MgH2(001) surface and a 15.5% decrease in E-act of the Si-doped gamma-MgH2(001) surface was deduced, while doping with Al and Si increased the activation energy barrier for the beta-MgH2 (001) surface drastically.

1 aKelkar, Tuhina1 aPal, Sourav uhttps://library.ncl.res.in/content/computational-study-electronic-structure-thermodynamics-and-kinetics-hydrogen-desorption-001892nas a2200169 4500008004100000022001400041245012200055210006900177260007100246300001400317490000800331520118500339100002401524700002601548700001601574856013201590 2009 eng d a1932-744700aDensity functional investigation of relativistic effects on the structure and reactivity of tetrahedral gold clusters0 aDensity functional investigation of relativistic effects on the  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcAPR a7101-71060 v1133 a

The influence of relativistic effects on the structure, vibrational modes, and reactivity of recently discovered tertrahedral gold clusters (Au(19) and Au(20)) are investigated using density functional methods. The intramolecular reactivity of the clusters was analyzed using density functional-based reactivity descriptors. The work shows that whereas the structural properties and vibrational modes are considerably affected by the relativistic effects, the reactivity trends based on Fukui function calculation on various atoms within this cluster remain unaffected by the absence or presence of relativistic effects. The reactivity descriptors reveal that the vertex atoms are the most reactive ones in Au(20) toward a nucleophilic attack. On the other hand, atoms connecting the missing vertex edge with the pyramid base along with the vertex atom are the most reactive for a nucleophilic attack in Au(19). The atoms lying at the center of each face are favorable for an electrophilic attack in both cases. Interestingly, the atoms with a missing cap in Aulg are highly favorable for electrophilic attack, and Au(20) has more sites for a favorable nucleophilic attack.

1 aDe, Himadri, Sekhar1 aKrishnamurty, Sailaja1 aPal, Sourav uhttps://library.ncl.res.in/content/density-functional-investigation-relativistic-effects-structure-and-reactivity-tetrahedral-001757nas a2200181 4500008004100000022001400041245016900055210006900224260012500293300001100418490000800429520092800437100001601365700002801381700001801409700001601427856013201443 2009 eng d a0021-960600aFirst- and second-order electrical properties computed at the FSMRCCSD level for excited states of closed-shell molecules using the constrained-variational approach0 aFirst and secondorder electrical properties computed at the FSMR aCIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USAbAMER INST PHYSICScJUL a0241020 v1313 a

Fock space multireference coupled-cluster (FSMRCC) method emerged as an efficient tool to describe the electronic structure of nearly degenerate cases. Development of linear response has been one of the challenging problems in FSMRCC due to the multiple-root nature of the effective Hamiltonian. A response from any of the roots would span the space for getting the properties. Hence, all roots perturbed by the external field would proliferate the excited states. We recently developed the FSMRCC method for the efficient evaluation of analytic response properties using a constrained variation approach. In this paper, we present analytic dipole moments and polarizabilities of H2O, O-3, and CH+ molecules in low-lying excited states along with brief discussion of singlet triplet decoupling of (1,1) sector of FSMRCC resulting from spin adaptation. (C) 2009 American Institute of Physics. [DOI: 10.1063/1.3167796]

1 aBag, Arijit1 aManohar, Prashant, Uday1 aVaval, Nayana1 aPal, Sourav uhttps://library.ncl.res.in/content/first-and-second-order-electrical-properties-computed-fsmrccsd-level-excited-states-closed-001394nas a2200229 4500008004100000022001400041245009600055210006900151260006800220300001400288490000800302520055300310653002000863653001800883653002900901100001900930700002700949700002400976700001601000700001601016856013201032 2009 eng d a0020-760800aIntermediate hamiltonian hilbert space coupled cluster method: theory and pilot application0 aIntermediate hamiltonian hilbert space coupled cluster method th a111 RIVER ST, HOBOKEN, NJ 07030 USAbJOHN WILEY & SONS INCcNOV a2909-29150 v1093 a

The intermediate Hamiltonian state universal (Hilbert-space) coupled-cluster method is presented, using a formalism similar to that developed for the valence universal (Fock-space) approach. The method is expected to be applicable to many states not accessible by traditional multiroot multireference all-order size-extensive approaches. A pilot application to excited states of atomic beryllium shows good convergence and agreement with experiment and full CI values. (C) 2009 Wiley Periodicals, Inc. Int J Quantum Chem 109: 2909-2915, 2009

10acoupled cluster10aHilbert space10aintermediate Hamiltonian1 aEliav, Ephraim1 aBorschevsky, Anastasia1 aShamasundar, K., R.1 aPal, Sourav1 aKaldor, Uzi uhttps://library.ncl.res.in/content/intermediate-hamiltonian-hilbert-space-coupled-cluster-method-theory-and-pilot-application-002126nas a2200217 4500008004100000022001400041245015500055210006900210260007300279300001100352490000800363520128100371653001501652653001401667653001901681653001801700653002501718100001901743700001601762856013001778 2009 eng d a0166-128000aIonization potential and structure relaxation of adenine, thymine, guanine and cytosine bases and their base pairs: a quantification of reactive sites0 aIonization potential and structure relaxation of adenine thymine aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcMAY a96-1020 v9023 a

We present density functional theory (DFT) calculations using B3LYP/6-31++G** method to show relaxation in geometry of base pairs on cation radical formation. The changes in hydrogen bond length and angles show that in the cationic radical form the structure of the base pairs relaxes due to the distribution of charge. According to a recent study. it has been found that, upon excitation hole transfer from base to sugar occurs which results in sugar radical formation and leads to strand breakage 145] [A. Kumar, M.D. Sevilla, J. Phys. Chem. B 110 (2006) 24181]. One hydrogen bond increases, while the other decreases in Adenine-Thymine (AT) base pair and in case of Guanine-Cytosine (GC) base pair. one bond increases and other two decrease. Same is the case with bond angles for both the base pairs. Analysis of the electron density map of Singly Occupied Molecular Orbital (SOMO) reveals that electron is transferred mainly from adenine and guanine bases in the cationic radical formation of AT and CC base pair, respectively. The reactive sites of bases have been analyzed using condensed Fukui functions in a relaxed and frozen core approximation. The effects of relaxation on the reactivity indices are also analyzed. (C) 2009 Elsevier B.V. All rights reserved.

10aBase-pairs10aDNA bases10aFukui function10aH-bond length10aIonization potential1 aMishra, Deepti1 aPal, Sourav uhttps://library.ncl.res.in/content/ionization-potential-and-structure-relaxation-adenine-thymine-guanine-and-cytosine-bases-001416nas a2200205 4500008004100000022001400041245009600055210006900151260006700220300001400287490000800301520065700309653001500966653002000981653001901001100002601020700001801046700001601064856013001080 2009 eng d a0020-760800aMagnetizability of doublet radicals using fock space multi-reference coupled cluster method0 aMagnetizability of doublet radicals using fock space multirefere a111 RIVER ST, HOBOKEN 07030-5774, NJ USAbWILEY-BLACKWELLcAUG a2191-21980 v1093 a

In this article, we report the first implementation of the recently developed Fock space multi reference Coupled cluster (FSMRCC) response approach for magnetizabilities. The FSM-RCC treats dynamic and static correlation in a very extensive manner. We report pilot application of the diarnagnetizability of NO, NO2, OH, and BH2 radicals. We also report preliminary applications of the paramagnetic magnetizability of the NO radical. Standard atom-centered Gaussian basis functions have been used, and this allowed US to Study the gauge dependence of the magnetizabilities. (C) 2009 Wiley Periodicals, Inc. Int J Quantum Chem 109: 2191-2198, 2009

10aFock space10amagnetizability10amultireference1 aRavichandran, Lalitha1 aVaval, Nayana1 aPal, Sourav uhttps://library.ncl.res.in/content/magnetizability-doublet-radicals-using-fock-space-multi-reference-coupled-cluster-method-001578nas a2200169 4500008004100000022001400041245011400055210006900169260007100238300001400309490000600323520089600329100001901225700001601244700001801260856013001278 2010 eng d a1549-961800aCalculation of dipole transition matrix elements and expectation values by vibrational coupled cluster method0 aCalculation of dipole transition matrix elements and expectation a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcOCT a3198-32040 v63 a

An effective operator approach based on the coupled cluster method is described and applied to calculate vibrational expectation values and absolute transition matrix elements. Coupled cluster linear response theory (CCLRT) is used to calculate excited states. The convergence pattern of these properties with the rank of the excitation operator is studied. The method is applied to a water molecule. Arponen-type double similarity transformation in extended coupled cluster (ECCM) framework is also used to generate an effective operator, and the convergence pattern of these properties is compared to the normal coupled cluster (NCCM) approach. It is found that the coupled cluster method provides an accurate description of these quantities for low lying vibrational excited states. The ECCM provides a significant improvement for the calculation of the transition matrix elements.

1 aBanik, Subrata1 aPal, Sourav1 aPrasad, Durga uhttps://library.ncl.res.in/content/calculation-dipole-transition-matrix-elements-and-expectation-values-vibrational-coupled-001958nas a2200169 4500008004100000022001400041245008900055210006900144260011000213300001400323490000700337520127300344100001701617700002101634700001601655856011701671 2010 eng d a1463-907600aCDASE-A reliable scheme to explain the reactivity sequence between Diels-Alder pairs0 aCDASEA reliable scheme to explain the reactivity sequence betwee aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcJUL a9328-93380 v123 a

The reliability of the Comprehensive Decomposition Analysis of Stabilization Energy (CDASE) scheme, proposed recently (Phys. Chem. Chem. Phys., 2009, 11, 8306), has been demonstrated in the present study. Reactivity sequence among more than 100 pairs, taking part in Diels-Alder (DA) reaction, is successfully generated by this scheme. The diene series consisted mainly of cis-1,3-butadiene and different substituted butadienes whereas dienophiles are mainly ethylene and its different substitutions. Both the positive energy component (i.e., the energy parameter defined as `internal assistance') and the negative energy component could generate the expected reactivity trend among the chosen DA pairs, which is also supported by the global electrophilicities of dienes and dienophiles and the corresponding charge-transfer values (Delta N). The numerical values of these components are capable of predicting even the `normal electron demand' (NED) and `inverse electron demand' (IED) nature of the corresponding DA reaction. The method is also capable of reproducing the lower reactivity of acetylene as dienophile when compared to that of ethylene. The reason for the success of CDASE-scheme in explaining intermolecular reactivity sequence is also analysed.

1 aSaha, Soumen1 aRoy, Ram, Kinkar1 aPal, Sourav uhttps://library.ncl.res.in/content/cdase-reliable-scheme-explain-reactivity-sequence-between-diels-alder-pairs-002125nas a2200181 4500008004100000022001400041245020900055210006900264260007100333300001400404490000800418520129500426100002301721700003001744700001601774700002401790856012901814 2010 eng d a1089-563900aComparison of the auxiliary density perturbation theory and the noniterative approximation to the coupled perturbed kohn-sham method: case study of the polarizabilities of disubstituted azoarene molecules0 aComparison of the auxiliary density perturbation theory and the  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcFEB a2357-23640 v1143 a

We present a theoretical study of the polarizabilities of free and disubstituted azoarenes employing auxiliary density perturbation theory (ADPT) and the noniterative approximation to the coupled perturbed Kohn-Sham (NIA-CPKS) method. Both methods are noniterative but use different approaches to obtain the perturbed density matrix. NIA-CPKS is different froth the conventional CPKS approach in that the perturbed Kohn-Sham matrix is obtained numerically, thereby yielding a single-step solution to CPKS. ADPT is an alternative approach to the analytical CPKS method in the framework of the auxiliary density functional theory. It is shown that the polarizabilities obtained using these two methods are in good agreement with each other. Comparisons are made for disubstituted azoarenes, which give support to the push-pull mechanism. Both methods reproduce the same trend for polarizabilities because of the substitution pattern of the azoarene moiety. Our results are consistent with the standard organic chemistry ``activating/deactivating'' sequence. We present the polarizabilities of the above molecules calculated with three different exchange-correlation functionals and two different auxiliary function sets. The computational advantages of both methods are also discussed.

1 aShedge, Sapana, V.1 aCarmona-Espindola, Javier1 aPal, Sourav1 aKoster, Andreas, M. uhttps://library.ncl.res.in/content/comparison-auxiliary-density-perturbation-theory-and-noniterative-approximation-coupled-001462nas a2200217 4500008004100000022001400041245010200055210006900157260006700226300001400293490000800307520068000315653001000995653000801005653002401013653002701037653001901064100001501083700001601098856013001114 2010 eng d a0020-760800aEffect of solvents having different dielectric constants on reactivity: a conceptual DFT approach0 aEffect of solvents having different dielectric constants on reac a111 RIVER ST, HOBOKEN 07030-5774, NJ USAbWILEY-BLACKWELLcAUG a1642-16470 v1103 a

Conceptual density functional theory is exploited to understand the reactivity in a medium of solvents with increasing dielectric constants. Aprotic as well as protic solvents are used for this study. It is found that the global parameters, such as chemical potential and hardness, decrease from gas phase to solvent phase with increasing dielectric constant. However, it is observed that the Fukui functions of the reactive atoms increase significantly with the dielectric constants of the aprotic solvents while for the protic solvents the variation of the reactivity indices is insignificant. (C) 2009 Wiley Periodicals, Inc. Int J Quantum Chem 110: 1642-1647, 2010

10aCOSMO10aDFT10adielectric constant10aReactivity descriptors10asolvent effect1 aKar, Rahul1 aPal, Sourav uhttps://library.ncl.res.in/content/effect-solvents-having-different-dielectric-constants-reactivity-conceptual-dft-approach-001191nas a2200205 4500008004100000022001400041245009000055210006900145260009200214300001800306490000800324520041200332653002000744653002400764653002300788653001500811653002000826100001600846856012300862 2010 eng d a0026-897600aFock space multi-reference coupled-cluster method for energies and energy derivatives0 aFock space multireference coupledcluster method for energies and a4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLANDbTAYLOR & FRANCIS LTDcOCT aPII 9279617140 v1083 a

In this article, the development of Fock space multi-reference coupled-cluster method is reviewed. Molecular applications of the method for excitation and ionisation energies which took place at Quantum Theory Project have been discussed. Later developments of the method for energy derivatives have been presented along with pilot applications of molecular properties of radicals and excited states.

10acoupled-cluster10adifference energies10aenergy derivatives10aFock space10aMulti-reference1 aPal, Sourav uhttps://library.ncl.res.in/content/fock-space-multi-reference-coupled-cluster-method-energies-and-energy-derivatives-001450nas a2200169 4500008004100000022001400041245013200055210006900187260007300256300001200329490000800341520073500349100002501084700002601109700001601135856012901151 2010 eng d a0009-261400aInfluence of plane wave cut-off on structural and electronic properties in Sn-BEA and Ti-BEA zeolite water molecule interaction0 aInfluence of plane wave cutoff on structural and electronic prop aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcJAN a374-3790 v4843 a

Periodic systems are best described by the pseudo-potential methods. However, the accuracy of its description depends on the cut-off of plane wave basis. This is much more critical in the case of weak interactions, where a clear understanding on the influence of plane wave cut-off on the structural and electronic properties is not readily available in the literature. In the present work, we have taken a metal substituted beta zeolite-H2O complex for understanding this objective. Our studies show that while a lower cut-off of 500 eV is sufficient for the convergence of the structural parameters, description of energy-dependent properties necessitates a high cut-off value. (C) 2009 Elsevier B.V. All rights reserved.

1 aKulkarni, Bhakti, S.1 aKrishnamurty, Sailaja1 aPal, Sourav uhttps://library.ncl.res.in/content/influence-plane-wave-cut-structural-and-electronic-properties-sn-bea-and-ti-bea-zeolite-002047nas a2200205 4500008004100000022001400041245013100055210006900186260010600255300001600361490000700377520119900384653001901583653002401602653002101626653002901647100002401676700001601700856012501716 2010 eng d a0360-319900aModel study of effect of M = Li+, Na+, Be2+, Mg2+, and Al3+ ion decoration on hydrogen adsorption of metal-organic framework-50 aModel study of effect of M Li Na Be2 Mg2 and Al3 ion decoration  aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLANDbPERGAMON-ELSEVIER SCIENCE LTDcDEC a12846-128570 v353 a

The effect of light metal ion decoration of the organic linker in metal organic framework MOF 5 on its hydrogen adsorption with respect to its hydrogen binding energy (Delta B E) and gravimetric storage capacity is examined theoretically by employing models of the form MC6H6 nH(2) where M = Li+ Na+ Be2+ Mg2+ and Al3+ A systematic investigation of the suitability of DFT functionals for studying such systems is also carried out Our results show that the interaction energy (Delta E) of the metal ion M with the benzene ring Delta B E and charge transfer (Q(trans)) from the metal to benzene ring exhibit the same increasing order Na+ < Li+ < Mg2+ < Be2+ < Al3+ Organic hnker decoration with the above metal ions strengthened H-2 MOF 5 interactions relative to its pure state However amongst these ions only Mg2+ ion resulted in Delta B E magnitudes that were optimal for allowing room temperature hydrogen storage applications of MOF 5 A much higher gravimetric storage capacity (6 15 wt % H-2) is also predicted for Mg2+ decorated MOF 5 as compared to both pure MOF 5 and Li+ decorated MOF (C) 2010 Professor T Nejat Veziroglu Published by Elsevier Ltd All rights reserved

10aBinding energy10aHydrogen adsorption10aHydrogen storage10aMetal organic frameworks1 aMaark, Tuhina, Adit1 aPal, Sourav uhttps://library.ncl.res.in/content/model-study-effect-m-li-na-be2-mg2-and-al3-ion-decoration-hydrogen-adsorption-metal-001499nas a2200181 4500008004100000022001400041245010100055210006900156260007300225300001200298490000800310520079000318100001801108700002101126700001601147700002301163856013101186 2010 eng d a0009-261400aMolecular electric dipole moments using the GVVPT2 variant of multireference perturbation theory0 aMolecular electric dipole moments using the GVVPT2 variant of mu aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcFEB a116-1210 v4873 a

A Lagrangian approach for electric dipoles within second order Generalized Van Vleck Perturbation Theory (GVVPT2) is presented. The Lagrangian approach for this response property requires that only one, perturbation-independent, set of simultaneous equations needs to be solved. The presented formulation is demonstrated numerically on several well studied molecules at their equilibrium bond lengths and on the complete potential energy curves of the ground and first excited states of LiH. Numerical corroboration of the expected continuity for molecular properties for the GVVPT2 method is observed. It is seen that the GVVPT2 electric dipoles are in good agreement with experiment and with other high accuracy theoretical methods. (C) 2010 Elsevier B.V. All rights reserved.

1 aTheis, Daniel1 aKhait, Yuriy, G.1 aPal, Sourav1 aHoffmann, Mark, R. uhttps://library.ncl.res.in/content/molecular-electric-dipole-moments-using-gvvpt2-variant-multireference-perturbation-theory-002926nas a2200229 4500008004100000022001400041245014300055210006900198260007300267300001000340490000800350520203500358653001702393653001802410653002702428653001702455653002702472100002502499700002602524700001602550856013002566 2010 eng d a1381-116900aProbing lewis acidity and reactivity of Sn- and Ti-beta zeolite using industrially important moieties: a periodic density functional study0 aProbing lewis acidity and reactivity of Sn and Tibeta zeolite us aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcAUG a36-430 v3293 a

The Lewis acidic nature and reactivity of two industrially important catalysts, viz.. Sn and Ti substituted beta zeolite (T-BEA) are analyzed using a unique combination of structural parameters, energetics and reactivity descriptors. To achieve this purpose, we adsorb the industrially important moieties (L) namely NH(3), H(2)O, CH(3)OH, CH(3)CN on the active sites of T-BEA. The calculations were performed using a periodic density functional method where the valence electrons are described using a plane wave basis set in conjunction with pseudo-potentials for the core electrons. The analysis of the structural properties of these complexes reveals that TO(4) shows typical characteristic splitting 120 degrees/90 degrees, close to bipyramidal geometry as compared to tetrahedral symmetry observed in the bare T-BEA. This is associated with small variations in the framework bond lengths (>= 0.08 angstrom) and a substantially large variation of bond angles (<= 10 degrees) in all the ligand-zeolite complexes. Further in both cases of Sn and Ti substituted beta zeolite, ligand interacts at optimum inter-atomic bond distance. Our interaction energies show that adsorption of all ligand moieties is stronger at Sn center than that of Ti. In general, the order of stability of the different T-BEA adducts is NH(3) > H(2)O > CH(3)OH > CH(3)CN. The ligand interaction is associated with the corresponding bond elongation and bond reduction of the adsorbed molecules on catalyst active site, which can be taken as measure of red or blue shifted frequencies. Finally, the global descriptors of reactivity justify the fact that soft acid, Sn-BEA, interacts strongly with soft bases following the Pearson's HSAB principle. However, hard acid, Ti-BEA interacts with soft bases to form a stable Lewis adduct. Furthermore, the HOMO-LUMO gap of all Sn-BEA-L adducts is lower than that of Ti-BEA-L adducts indicating to its higher Lewis acidic nature compared to Ti-BEA. (C) 2010 Elsevier B.V. All rights reserved.

10aBeta zeolite10aLewis acidity10aLigand-zeolite complex10aPeriodic-DFT10aReactivity descriptors1 aKulkarni, Bhakti, S.1 aKrishnamurty, Sailaja1 aPal, Sourav uhttps://library.ncl.res.in/content/probing-lewis-acidity-and-reactivity-sn-and-ti-beta-zeolite-using-industrially-important-000678nas a2200169 4500008004100000245011800041210006900159260003100228300001200259490000700271100002800278700002400306700001600330700001800346700001600364856012800380 2010 eng d00aOn some aspects of fock-space multi-reference coupled-cluster singles and doubles energies and optical properties0 asome aspects of fockspace multireference coupledcluster singles  aNetherlandsbSpringercAPR a375-3930 v111 aManohar, Prashant, Uday1 aShamasundar, K., R.1 aBag, Arijit1 aVaval, Nayana1 aPal, Sourav uhttps://library.ncl.res.in/content/some-aspects-fock-space-multi-reference-coupled-cluster-singles-and-doubles-energies-and00820nas a2200169 4500008004100000022001400041245013700055210006900192260007100261300001400332490000800346520014600354100002400500700002600524700001600550856008400566 2010 eng d a1932-744700aUnderstanding the reactivity properties of Au-n (6 <= n <= 13) clusters using density functional theory based reactivity descriptors0 aUnderstanding the reactivity properties of Aun 6 n 13 clusters u a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcAPR a6690-67030 v1143 a

{Relativistic density functional theory (DFT) based calculations have been performed on gold clusters with six to thirteen atoms (Au-n

1 aDe, Himadri, Sekhar1 aKrishnamurty, Sailaja1 aPal, Sourav uhttps://library.ncl.res.in/content/understanding-reactivity-properties-au-n-6-002480nas a2200229 4500008004100000022001400041245009600055210006900151260010600220300001600326490000700342520157700349653002701926653003001953653003001983653002102013653003202034100001702066700002402083700001602107856012702123 2011 eng d a0360-319900aAb initio and periodic DFT investigation of hydrogen storage on light metal-decorated MOF-50 aAb initio and periodic DFT investigation of hydrogen storage on  aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLANDbPERGAMON-ELSEVIER SCIENCE LTDcAUG a10816-108270 v363 a

The effect of light metal (M = Li, Be, Mg, and Al) decoration on the stability of metal organic framework MOF-5 and its hydrogen adsorption is investigated by ab initio and periodic density functional theory (DFT) calculations by employing models of the form BDC:M-2:nH(2) and MOF-5:M-2:nH(2), where BDC stands for the benzenedicarboxylate organic linker and MOF-5 represents the primitive unit cell. The suitability of the periodic DFT method employing the GGA-PBE functional is tested against MP2/6-311 + G* and MP2/cc-pVTZ molecular calculations. A correlation between the charge transfer and interaction energies is revealed. The metal-MOF-5 interactions are analyzed using the frontier molecular orbital approach. Difference charge density plots show that H-2 molecules get polarized due to the charge generated on the metal atom adsorbed over the BDC linker, resulting in electrostatic guest-host interactions. Our solid state results show that amongst the four metal atoms, Mg and Be decoration does not stabilize the MOF-5 to any significant extent. Li and Al decoration strengthened the H-2-MOE-5 interactions relative to the pure MOF-5 exhibited by the enhanced binding energies. The hydrogen binding energies for the Li- and Al-decorated MOF-5 were found to be sensible for allowing reversible hydrogen storage at ambient temperatures. A high hydrogen uptake of 4.3 wt.% and 3.9 wt.% is also predicted for the Li- and Al-decorated MOF-5, respectively. Copyright (C) 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

10aab initio calculations10aDensity functional theory10aHydrogen binding energies10aHydrogen storage10aMetal-Pi-Arene interactions1 aDixit, Mudit1 aMaark, Tuhina, Adit1 aPal, Sourav uhttps://library.ncl.res.in/content/ab-initio-and-periodic-dft-investigation-hydrogen-storage-light-metal-decorated-mof-5-001156nas a2200169 4500008004100000022001400041245009200055210006900147260007100216300001200287490000600299520050100305100002600806700001800832700001600850856012000866 2011 eng d a1549-961800aEffect of triples to dipole moments in fock-space multireference coupled cluster method0 aEffect of triples to dipole moments in fockspace multireference  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcAPR a876-8830 v73 a

In this paper, we present the new implementation of partial triples for the dipole moment of doublet radicals in Lagrangian formulation of Fock-space multireference coupled cluster (A-FSMRCC) response method. We have implemented a specific scheme of noniterative triples, in addition to singles and doubles schemes, which accounts for the effects appearing at least at the third order in dipole moments. The method is applied to the ground states of OH, OOH, HCOO, CN, CH, and PO radicals.

1 aRavichandran, Lalitha1 aVaval, Nayana1 aPal, Sourav uhttps://library.ncl.res.in/content/effect-triples-dipole-moments-fock-space-multireference-coupled-cluster-method-000844nas a2200181 4500008004100000022001400041245011600055210006900171260007100240300001600311490000800327520014800335100002400483700002600507700001900533700001600552856009400568 2011 eng d a1932-744700aFinite temperature behavior of gas phase neutral Au-n (3 <= n <= 10) clusters: a first principles investigation0 aFinite temperature behavior of gas phase neutral Aun 3 n 10 clus a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcSEP a17278-172850 v1153 a

{Relativistic density functional theory (DFT) based molecular dynamical simulations are performed on gold clusters with 3-10 atoms (Au-n

1 aDe, Himadri, Sekhar1 aKrishnamurty, Sailaja1 aMishra, Deepti1 aPal, Sourav uhttps://library.ncl.res.in/content/finite-temperature-behavior-gas-phase-neutral-au-n-3-001981nas a2200169 4500008004100000022001400041245014900055210006900204260007100273300001600344490000800360520124700368100002501615700002601640700001601666856012901682 2011 eng d a1932-744700aSize- and shape-sensitive reactivity behavior of Al-n(n=2-5, 13, 30, and 100) clusters toward the N-2 molecule: a first-principles investigation0 aSize and shapesensitive reactivity behavior of Alnn25 13 30 and  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcAUG a14615-146230 v1153 a

Reactivity of aluminum clusters has been found to exhibit size-sensitive variations. N-2 reduction is a hard process, and its dissociation on the Al surface is one of the few chemical methods available under nonhazardous conditions. In this context, we attempt to understand the adsorption behavior of N-2 molecules as a function of varying size and shape of Al clusters using a Density Functional Theory (DFT) based method. During the complex formation, various N-2 adsorption modes are examined. The results clearly demonstrate that, while the interaction energy does not vary with respect to the cluster size, shape of the cluster is highly contributive toward the chemisorption (a prerequisite for the reactivity) of the N-2 molecule. The underlying electronic and structural factors influencing the adsorption of N-2 molecules on the Al clusters are analyzed with the help of the Electron Localization Function (ELF) and Frontier Molecular Orbitals. As an illustration, the activation barrier calculations on various Al-13 conformations are calculated, and results confirm the experimental propositions that high-energy structures (depending upon their geometrical and electronic orientation) are more favorable for N-2 reduction.

1 aKulkarni, Bhakti, S.1 aKrishnamurty, Sailaja1 aPal, Sourav uhttps://library.ncl.res.in/content/size-and-shape-sensitive-reactivity-behavior-al-nn2-5-13-30-and-100-clusters-toward-n-2-002601nas a2200217 4500008004100000022001400041245011400055210006900169260009200238300001200330490000700342520176600349653000802115653000902123653002802132653003302160100001902193700001602212700002602228856012902254 2011 eng d a0892-702200aUnderstanding the molecular conformations of Na-dimyristoylphosphatidylglycerol (DMPG) using DFT-based method0 aUnderstanding the molecular conformations of Nadimyristoylphosph a4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLANDbTAYLOR & FRANCIS LTDcAUG a953-9630 v373 a

The molecular conformations of phospholipids comprising a lipid bilayer determine the physico-chemical properties of the latter. In this study, we attempt to understand the various possible conformations available for an anionic lipid molecule dimyristoylphosphatidylglycerol (DMPG) with Na as its charge-compensating cation. The various possible molecular orientations available for lipid molecule are analysed using a density functional theory-based method. Our study reveals a rich conformational space with two different types of glycerol body orientations, more commonly known as rotamers. Interestingly, this is in agreement with the molecular conformations proposed earlier by NMR studies on lipid monomer solutions. We demonstrate that these conformations are an outcome of delicate balance of electrostatic and van der Waals forces along with intra-molecular hydrogen bonds achieved by a critical combination of torsion angles. Na(+) ions are seen to interact predominantly with the oxygen atoms of the glycerol groups in tail and head along with that of phosphate oxygen atoms leading to a cage-like orientation of lipid molecule around the Na(+). Following the conformational analysis, we attempt to evaluate the electronic properties of few low-lying conformations. This study shows that though the water molecules screen the Na-O(lipid) interactions, they do not dramatically modify the Na-O(lipid) bond distances. The lipid conformation retains the cage-like structure around the Na(+) in the presence of water molecules. Some amount of charge transfer from the water molecules to Na ion is noted. The water molecules modify the phosphate-tail glycerol group interactions leading to a more stable Na-DMPG-H(2)O and Na-DMPG-4H(2)O complexes.

10aDFT10aDMPG10amolecular conformations10arotamer and hydration energy1 aMishra, Deepti1 aPal, Sourav1 aKrishnamurty, Sailaja uhttps://library.ncl.res.in/content/understanding-molecular-conformations-na-dimyristoylphosphatidylglycerol-dmpg-using-dft-001566nas a2200169 4500008004100000022001400041245019600055210006900251260007300320300001200393490000800405520079500413100002301208700001601231700002501247856012401272 2011 eng d a0009-261400aValidation and application of auxiliary density perturbation theory and non-iterative approximation to coupled-perturbed Kohn-Sham approach for calculation of dipole-quadrupole polarizability0 aValidation and application of auxiliary density perturbation the aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcJUL a185-1900 v5103 a

Recently, two non-iterative approaches have been proposed to calculate response properties within density functional theory (DFT). These approaches are auxiliary density perturbation theory (ADPT) and the non-iterative approach to the coupled-perturbed Kohn-Sham (NIA-CPKS) method. Though both methods are non-iterative, they use different techniques to obtain the perturbed Kohn-Sham matrix. In this Letter, for the first time, both of these two independent methods have been used for the calculation of dipole-quadrupole polarizabilities. To validate these methods, three tetrahedral molecules viz., P-4; CH4 and adamantane (C10H16) have been used as examples. The comparison with MP2 and CCSD proves the reliability of the methodology. (C) 2011 Elsevier B. V. All rights reserved.

1 aShedge, Sapana, V.1 aPal, Sourav1 aKoester, Andreas, M. uhttps://library.ncl.res.in/content/validation-and-application-auxiliary-density-perturbation-theory-and-non-iterative-002149nas a2200229 4500008004100000022001400041245011300055210006900168260005700237300000900294490000800303520130600311653000801617653003301625653003701658653002301695653001301718100002301731700002201754700001601776856012701792 2012 eng d a1432-881X00aBehaviour of density functional theory for electric response properties at distorted geometries of molecules0 aBehaviour of density functional theory for electric response pro a233 SPRING ST, NEW YORK, NY 10013 USAbSPRINGERcFEB a10940 v1313 a

The role of exchange-correlation is well known for accurate calculations of electric response properties. The exchange-correlation functional in density functional theory (DFT) has been well studied for ground state equilibrium geometry. However, the behaviour of these functional in stretched geometries, where static correlation play an important role, has not been studied systematically, particularly for response electric properties. Thus, we present here the rigorous calculation of electric response properties at distorted geometries of the molecules. We have considered dipole polarizability and dipole-quadrupole polarizability for description of role of static and dynamic correlation for electric response properties. The calculations are performed with our new approach, noniterative approximation to coupled-perturbed Kohn-Sham method. These DFT results are compared with higher level ab initio such as coupled perturbed singles and doubles and fully correlated full CI. We have studied single, double and triple-bonded systems at different inter-nuclear separation. We report here the dipole polarizability and dipole-quadrupole polarizability of HF, BH, H2CO, CO and NO+. We also present the effect of basis and functional on polarizability and dipole-quadrupole polarizability.

10aDFT10aDipole-dipole polarizability10aDipole-quadrupole polarizability10aDistorted geometry10aNIA-CPKS1 aShedge, Sapana, V.1 aJoshi, Sayali, P.1 aPal, Sourav uhttps://library.ncl.res.in/content/behaviour-density-functional-theory-electric-response-properties-distorted-geometries-001176nas a2200205 4500008004100000022001400041245009800055210006900153260011000222300001400332490000700346520034900353100002200702700002200724700002700746700001600773700002400789700002800813856012900841 2012 eng d a1477-052000aConformational modulation of Ant-Pro oligomers using chirality alteration of proline residues0 aConformational modulation of AntPro oligomers using chirality al aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcSEP a8426-84330 v103 a

Structural modulation of Ant-Pro (anthranilic acid-proline) oligomers has been carried out by chirality alteration of the proline residues. The results suggest that the chirality altered oligomers show well-defined helical conformation featuring nine-membered hydrogen bonding interactions - without compromising conformational rigidity.

1 aKale, Sangram, S.1 aKotmale, Amol, S.1 aDutta, Achintya, Kumar1 aPal, Sourav1 aRajamohanan, P., R.1 aSanjayan, Gangadhar, J. uhttps://library.ncl.res.in/content/conformational-modulation-ant-pro-oligomers-using-chirality-alteration-proline-residues-001533nas a2200229 4500008004100000022001400041245012200055210006900177260007300246300001000319490000800329520062400337653003700961653004700998653003601045653002201081100001701103700002001120700001601140700001801156856012901174 2012 eng d a0301-010400aConstrained variational approach for energy derivatives in Intermediate hamiltonian fock-space coupled-cluster theory0 aConstrained variational approach for energy derivatives in Inter aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcJUN a45-490 v4013 a

Fock-space multi-reference coupled cluster theory is an efficient method for electronic structure of nearly degenerate cases. However, it suffers from the intruder state problem for large model space. The intermediate Hamiltonian formulation eliminates intruder state problem and helps in the convergence of equations. In this paper we have implemented intermediate Hamiltonian approach in Fock-space coupled cluster method for the response properties. We test our method for the dipole moments of doublet radicals. We report dipole moments of CN, SF and NS radicals. (C) 2011 Elsevier B. V. All rights reserved.

10aConstrained variational approach10aFock-space multi-reference coupled cluster10aIntermediate Hamiltonian theory10aResponse approach1 aGhosh, Aryya1 aGupta, Jitendra1 aPal, Sourav1 aVaval, Nayana uhttps://library.ncl.res.in/content/constrained-variational-approach-energy-derivatives-intermediate-hamiltonian-fock-space-001342nas a2200253 4500008004100000020004100041022001400082245008500096210006900181260006700250300001200317490000800329520042300337653004100760653002600801653003400827653000900861653001500870653003300885100001600918700001700934700002200951856011500973 2012 eng d a978-3-642-32753-7; 978-3-642-32752-0 a0081-599300aDescriptors as probes for inter-molecular interactions and external perturbation0 aDescriptors as probes for intermolecular interactions and extern a233 Spring Street, New York, NY 10013, United StatesbSpringer a131-1580 v1493 a

In this article, different reactivity descriptors have been reviewed. Conceptual density functional theory is an important area where a lot of interesting developments in terms of descriptors and molecule interactions have taken place in recent years. This review will highlight our own work on such development of descriptors and their applications to characterise stability and reactivity in molecule systems.

10aConceptual density functional theory10aElectric field effect10aGlobal reactivity descriptors10aHSAB10aLocal HSAB10aLocal reactivity descriptors1 aPal, Sourav1 aPutz, M., V.1 aMingos, D., M. P. uhttps://library.ncl.res.in/content/descriptors-probes-inter-molecular-interactions-and-external-perturbation-001124nas a2200169 4500008004100000022001400041245007900055210006900134260012500203300001100328490000800339520045400347100001700801700001800818700001600836856010200852 2012 eng d a0021-960600aEquation-of-motion coupled-cluster method for the study of shape resonance0 aEquationofmotion coupledcluster method for the study of shape re aCIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USAbAMER INST PHYSICScJUN a2341100 v1363 a

The equation-of-motion coupled-cluster method (EOM-CC) is applied for the first time to calculate the energy and width of a shape resonance in an electron-molecule scattering. The procedure is based on inclusion of complex absorbing potential with EOM-CC theory. We have applied this method to investigate the shape resonance in e(-)N(2), e(-)CO, and e(-)C(2)H(2). (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4729464]

1 aGhosh, Aryya1 aVaval, Nayana1 aPal, Sourav uhttps://library.ncl.res.in/content/equation-motion-coupled-cluster-method-study-shape-resonance-001711nas a2200217 4500008004100000022001400041245007900055210006900134260007300203300001000276490000800286520092600294653002901220653003001249653002201279100002201301700002701323700001601350700001801366856010901384 2012 eng d a0301-010400aExtended coupled cluster for Raman and infrared spectra of small molecules0 aExtended coupled cluster for Raman and infrared spectra of small aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcJUL a25-320 v4033 a

In this paper we study the harmonic vibrational frequencies, infrared (IR) intensities, Raman intensities and depolarization ratio using extended coupled cluster method. Raman and IR intensities are mixed derivatives of energy with respect to the electric field and geometric perturbation whereas vibrational frequencies are derivatives of energy with respect to geometry. We use semi-numerical approach to obtain these derivatives. We have studied the effect of electron correlation and basis set for the above properties. We compare our results with non-variational coupled cluster and experimental values, wherever available. We have studied HF, BH, CH+, CO and H2CO molecules in different basis sets. For HF molecule, benchmarking is done with full CI values and basis set convergence is studied for this molecule. Effect of triples is studied for all the molecules. (C) 2012 Elsevier B.V. All rights reserved.

10aExtended coupled cluster10aIR and Raman spectroscopy10aMixed derivatives1 aJoshi, Sayali, P.1 aDutta, Achintya, Kumar1 aPal, Sourav1 aVaval, Nayana uhttps://library.ncl.res.in/content/extended-coupled-cluster-raman-and-infrared-spectra-small-molecules-001859nas a2200229 4500008004100000022001400041245010400055210006900159260007300228300001200301490000800313520098400321653001801305653004001323653003001363653002201393653002501415100002401440700002601464700001601490856012301506 2012 eng d a0920-586100aFirst principle investigation on the thermal stability of a golden fullerene: a case study of Au-320 aFirst principle investigation on the thermal stability of a gold aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcDEC a106-1090 v1983 a

Structural and electronic properties of Au-32 cluster are analyzed using relativistic density functional theory (DFT) based methods. Further, DFT based molecular dynamical (MD) simulations are performed on Au-32 golden fullerene with an aim of understanding its thermal stability at various working temperatures. Various conformations being populated at different temperatures of a cluster are analyzed. The study shows that the ground state icosahedral conformation is stable only up to 300 K and structure remains in a hollow conformation only up to 400 K. This clearly explains the reasons for failure by experimentalists in trapping the unique fullerene conformation in spite of the theoretical predictions of it being a very stable one. The above MD study also indicates that the bare fullerene Au-32 cluster (without any stabilizing ligands) can be used for potential catalytic applications only around room temperatures. (C) 2012 Elsevier B. V. All rights reserved.

10aAu-32 cluster10aBorn-Oppenheimer molecular dynamics10aDensity functional theory10aGolden fullerenes10aRelativistic effects1 aDe, Himadri, Sekhar1 aKrishnamurty, Sailaja1 aPal, Sourav uhttps://library.ncl.res.in/content/first-principle-investigation-thermal-stability-golden-fullerene-case-study-au-32-000637nas a2200157 4500008004100000245012300041210006900164260000800233300001200241490000800253100002600261700002700287700001800314700001600332856013100348 2012 eng d00aFock-space multi-reference coupled-cluster response with the effect of triples on dipole moment of ClO and SF radicals0 aFockspace multireference coupledcluster response with the effect cJAN a223-2320 v1241 aRavichandran, Lalitha1 aBhattacharya, Debarati1 aVaval, Nayana1 aPal, Sourav uhttps://library.ncl.res.in/content/fock-space-multi-reference-coupled-cluster-response-effect-triples-dipole-moment-clo-and-sf01336nas a2200229 4500008004100000022001400041245009600055210006900151260011000220300001400330490000700344520043900351100001700790700002200807700002300829700001900852700001600871700002600887700003500913700002800948856013000976 2012 eng d a1359-734500aHelical folding in heterogeneous foldamers without inter-residual backbone hydrogen-bonding0 aHelical folding in heterogeneous foldamers without interresidual aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcJUL a8922-89240 v483 a

This communication describes a set of hybrid foldamers that do not feature inter-residual, but intra-residual backbone hydrogen-bonding, yet adopt a preferentially folded conformation displaying right-handed helical architecture. Conformational ordering is apparently due to the combined conformational restrictions imposed by the conformationally restricted individual amino acid residues with which the oligomers are made of.

1 aPriya, Gowri1 aKotmale, Amol, S.1 aGawade, Rupesh, L.1 aMishra, Deepti1 aPal, Sourav1 aPuranik, Vedavati, G.1 aRajamohanan, Pattuparambil, R.1 aSanjayan, Gangadhar, J. uhttps://library.ncl.res.in/content/helical-folding-heterogeneous-foldamers-without-inter-residual-backbone-hydrogen-bonding-001731nas a2200169 4500008004100000022001400041245009200055210006900147260007100216300001400287490000600301520107000307100002701377700001801404700001601422856012301438 2012 eng d a1549-961800aNOx catalyzed pathway of stratospheric ozone depletion: a coupled cluster investigation0 aNOx catalyzed pathway of stratospheric ozone depletion a coupled a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcMAY a1895-19010 v83 a

We report a theoretical investigation on the NOx catalyzed pathways of stratospheric ozone depletion using highly accurate coupled cluster methods. These catalytic reactions represent a great challenge to state-of-the-art ab initio methods, while their mechanisms remain unclear to both experimentalists and theoreticians. In this work, we have used the so-called ``gold standard of quantum chemistry,'' the CCSD(T) method, to identify the saddle points on NOx-based reaction pathways of ozone hole formation. Energies of the saddle points are calculated using the multireference variants of coupled cluster methods. The calculated activation energies and rate constants show good agreement with available experimental results. Tropospheric precursors to stratospheric NOx radicals have been identified, and their potential importance in stratospheric chemistry has been discussed. Our calculations resolve previous conflicts between ab initio and experimental results for a trans nitro peroxide intermediate, in the NOx catalyzed pathway of ozone depletion.

1 aDutta, Achintya, Kumar1 aVaval, Nayana1 aPal, Sourav uhttps://library.ncl.res.in/content/nox-catalyzed-pathway-stratospheric-ozone-depletion-coupled-cluster-investigation-001582nas a2200193 4500008004100000022001400041245013800055210006900193260007100262300001600333490000800349520080600357100001701163700002401180700002101204700001701225700001601242856013001258 2012 eng d a1932-744700aScandium-decorated MOF-5 as potential candidates for room-temperature hydrogen storage: a solution for the clustering problem in MOFs0 aScandiumdecorated MOF5 as potential candidates for roomtemperatu a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcAUG a17336-173420 v1163 a

Transition-metal-based systems show promising binding energy for hydrogen storage but suffer from clustering problem. The effect of light transition metal (M = Sc, Ti) decoration, boron substitution on the hydrogen storage properties of MOF-5, and clustering problem of metals has been investigated using ab initio density, functional theory. Our results of solid-tate calculations reveal that whereas Ti clusters strongly Sc atoms do not suffer from this problem when decorating MOF-5. Boron substitution on metal-decorated MOF-5 enhances the interaction energy of both the metals with MOF-5. Sc-decorated MOF-5 shows a hydrogen storage capacity of 5.81 wt % with calculated binding energies of 20-40 kJ/mol, which ensures the room-teniperature applicability of this hydrogen storage material.

1 aDixit, Mudit1 aMaark, Tuhina, Adit1 aGhatak, Kamalika1 aAhuja, Rajiv1 aPal, Sourav uhttps://library.ncl.res.in/content/scandium-decorated-mof-5-potential-candidates-room-temperature-hydrogen-storage-solution-001578nas a2200169 4500008004100000022001400041245012000055210006900175260007300244300001200317490000800329520087600337100002301213700001601236700002501252856013101277 2012 eng d a0009-261400aTheoretical study of frequency and temperature dependence of dipole-quadrupole polarizability of P-4 and adamantane0 aTheoretical study of frequency and temperature dependence of dip aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcNOV a146-1500 v5523 a

The frequency and temperature dependence of dipole-quadrupole polarizability of tetrahedral P-4 and adamantane molecules have been studied using first-principle all-electron density functional theory calculation. The recently developed time-dependent auxiliary density functional theory is extended for the calculation of dynamic dipole-quadrupole polarizabilities. Temperature effects are incorporated by Born-Oppenheimer molecular dynamics (BOMD) simulations recorded up to 100 ps. The dynamic dipole-quadrupole polarizabilities are calculated along these trajectories. The frequency and temperature effects can be significant for the accurate calculation of dipole-quadrupole polarizability. We have also identified the main reason for the observed discrepancy between experiment and theory in the case of adamantane. (c) 2012 Elsevier B.V. All rights reserved.

1 aShedge, Sapana, V.1 aPal, Sourav1 aKoester, Andreas, M. uhttps://library.ncl.res.in/content/theoretical-study-frequency-and-temperature-dependence-dipole-quadrupole-polarizability-p-001223nas a2200169 4500008004100000022001400041245008100055210006900136260012500205300001100330490000800341520053600349100001900885700001600904700001800920856011500938 2012 eng d a0021-960600aVibrational multi-reference coupled cluster theory in bosonic representation0 aVibrational multireference coupled cluster theory in bosonic rep aCIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USAbAMER INST PHYSICScSEP a1141080 v1373 a

The vibrational multi-reference coupled cluster method is developed to calculate the vibrational excitation energies of polyatomic molecules. The method is implemented on ozone and formaldehyde molecules and the results are compared with full vibrational configuration interaction (FVCI) method. A good agreement is found between the vibrational multi-reference coupled cluster method and converged FVCI method for lower lying vibrational states. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4753422]

1 aBanik, Subrata1 aPal, Sourav1 aPrasad, Durga uhttps://library.ncl.res.in/content/vibrational-multi-reference-coupled-cluster-theory-bosonic-representation-000995nas a2200181 4500008004100000022001400041245007700055210006900132260011000201300001600311490000700327520030700334100001700641700002200658700001600680700001800696856009900714 2013 eng d a1463-907600aCAP/EOM-CCSD method for the study of potential curves of resonant states0 aCAPEOMCCSD method for the study of potential curves of resonant  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcSEP a17915-179210 v153 a

The equation-of-motion coupled-cluster (EOM-CC) method along with the complex absorbing potential (CAP) is used for the study of resonance in e(-)-N-2 and e(-)-CO. Resonance position and width are studied as a function of bond length. We report the potential curves (PC) of the resonance states.

1 aGhosh, Aryya1 aKarne, Anagha, S.1 aPal, Sourav1 aVaval, Nayana uhttps://library.ncl.res.in/content/capeom-ccsd-method-study-potential-curves-resonant-states-001986nas a2200169 4500008004100000022001400041245016600055210006900221260012500290300001100415490000800426520119300434100002701627700001801654700001601672856012801688 2013 eng d a0021-960600aElectronic transition dipole moments and dipole oscillator strengths within fock-space multi-reference coupled cluster framework: an efficient and novel approach0 aElectronic transition dipole moments and dipole oscillator stren aCIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USAbAMER INST PHYSICScMAR a0941080 v1383 a

Within the Fock-space multi-reference coupled cluster framework, we have evaluated the electronic transition dipole moments, which determine absorption intensities. These depend on matrix elements between two different wave functions (e. g., ground state to the excited state). We present two different ways, to calculate these transition moments. In the first method, we construct the ground and excited state wave functions with the normal exponential ansatz of Fock-space coupled cluster method and then calculate the relevant off-diagonal matrix elements. In the second approach, we linearize the exponential form of the wave operator which will generate the left vector, by use of Lagrangian formulation. The right vector is obtained from the exponential ansatz. In order to relate the transition moments to oscillator strengths, excitation energies need to be evaluated. The excitation energies are obtained from the Fock-space multi-reference framework. The transition dipole moments of the ground to a few excited states, together with the oscillator strengths of a few molecules, are presented. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4793277]

1 aBhattacharya, Debarati1 aVaval, Nayana1 aPal, Sourav uhttps://library.ncl.res.in/content/electronic-transition-dipole-moments-and-dipole-oscillator-strengths-within-fock-space-001805nas a2200229 4500008004100000022001400041245011500055210006900170260007300239300001000312490000800322520095000330653001801280653002201298653002901320100002001349700002801369700001701397700001801414700001601432856012701448 2013 eng d a0301-010400aExtended coupled cluster through nth perturbation order for molecular response properties: a comparative study0 aExtended coupled cluster through nth perturbation order for mole aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcMAY a45-510 v4173 a

In this paper, we have presented and analyzed the extended coupled cluster (ECC) energy functional, truncated up to nth perturbation order in which expansion is limit to operators of the single and double excitations. The expression for the first order energy derivatives based on the above truncation schemes has been derived and numerically analyzed. We have done a comparative study for dipole moment in various perturbative ECC (n) methods (2 <= n <= 5) for three systems (HF, H2O and BH) at equilibrium geometry. We have particularly studied two variants of ECC (4) and ECC (5*) method for stretched geometry. We have analyzed the contribution of important terms present in ECC functional based on perturbative argument. We have compared our results with standard coupled cluster (CCSD) as well as cubic truncated ECC and also benchmarked with the full CI results wherever available. (c) 2013 Elsevier B.V. All rights reserved.

10aDipole moment10aEnergy functional10aExtended coupled cluster1 aGupta, Jitendra1 aManohar, Prashant, Uday1 aGhosh, Aryya1 aVaval, Nayana1 aPal, Sourav uhttps://library.ncl.res.in/content/extended-coupled-cluster-through-nth-perturbation-order-molecular-response-properties-001243nas a2200205 4500008004100000022001400041245007900055210006900134260006700203300001400270490000800284520045300292653004600745653005300791653002000844100002700864700001800891700001600909856011200925 2013 eng d a0020-760800aFock space multireference coupled cluster theory: study of shape resonance0 aFock space multireference coupled cluster theory study of shape  a111 RIVER ST, HOBOKEN 07030-5774, NJ USAbWILEY-BLACKWELLcJUN a1690-16950 v1133 a

The complex absorbing potential along with correlated independent particle potential (CIP) Fock space multireference coupled cluster method is used for the study of resonances. We have studied shape resonance of e(-) - F-2, e(-) - N2O and e(-) -CO molecules. In particular, we have studied e(-) - F-2 scattering at different bond lengths to know whether F-2(-) is bound at the equilibrium bond length of F-2. (C) 2013 Wiley Periodicals, Inc.

10acorrelated independent particle potential10aFock-space multireference coupled cluster theory10ashape resonance1 aBhattacharya, Sumantra1 aVaval, Nayana1 aPal, Sourav uhttps://library.ncl.res.in/content/fock-space-multireference-coupled-cluster-theory-study-shape-resonance-001284nas a2200193 4500008004100000022001400041245022000055210006900275260011000344300001600454490000600470520037000476100001900846700003100865700002700896700001900923700001600942856013200958 2013 eng d a2046-206900aHighly concise and practical route to clavaminols, sphinganine and (+)-spisulosine via indium mediated allylation of alpha-hydrazino aldehyde and a theoretical insight into the stereochemical aspects of the reaction0 aHighly concise and practical route to clavaminols sphinganine an aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcJUL a15442-154480 v33 a

A conceptually different approach has been employed for the synthesis of 1,2-amino alcohols by proline-catalyzed alpha-amination of aldehyde and one-pot indium mediated allylation of the crude alpha-hydrazino aldehydes. DFT based quantum chemical calculations have been performed to obtain a quantitative explanation of the stereoselectivity of the reaction.

1 aPandey, Menaka1 aChowdhury, Partha, Sarathi1 aDutta, Achintya, Kumar1 aKumar, Pradeep1 aPal, Sourav uhttps://library.ncl.res.in/content/highly-concise-and-practical-route-clavaminols-sphinganine-and-spisulosine-indium-mediated-002344nas a2200169 4500008004100000022001400041245011700055210006900172260007100241300001600312490000800328520165200336100001701988700001602005700002602021856012702047 2013 eng d a1932-744700aInfluence of charge and ligand on the finite temperature behavior of gold clusters: a BOMD study on Au-6 cluster0 aInfluence of charge and ligand on the finite temperature behavio a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcOCT a20982-209900 v1173 a

Conformation and electronic charge on a gold cluster are known to determine its catalytic property. However, little is known on the finite temperature behavior of various gold cluster conformations. Much less is known on the role of charge or a ligand in stabilizing a conformation at finite temperatures. In this work, we have carried out relativistic density functional theory (DFT) based molecular dynamical simulations on neutral and charged Au-6 clusters with an aim of understanding the stability of ground state conformations as a function of charge on the cluster. Our simulations reveal that cationic and anionic Au-6 clusters undergo conformational transitions at 500 K where as neutral Au-6 cluster retains its ground state conformation up to a temperature of 1100 K. In order to look into the factors leading to the stabilization of neutral Au-6 cluster (or destabilization of cationic and anionic Au-6 clusters), structural and electronic properties are analyzed. Factors such as charge redistribution within the atoms and composition of molecular orbitals are seen to contribute towards stronger Au-Au bonds in Au-6(0) thereby stabilizing it considerably. Following the analysis, simulations are also extended to neutral, cationic, and anionic Au-6-COn (n = 1,2) complexes. In the case of CO chemisorbed Au-6 clusters, neutral and negatively charged ground state conformations are stable up to nearly 800 K, while the positively charged Au-6 ground state conformation collapses at room temperature. This work, in short demonstrates how charge or even a ligand can be used to moderate the physical properties of a gold cluster.

1 aManzoor, Dar1 aPal, Sourav1 aKrishnamurty, Sailaja uhttps://library.ncl.res.in/content/influence-charge-and-ligand-finite-temperature-behavior-gold-clusters-bomd-study-au-6-001187nas a2200217 4500008004100000022001400041245008400055210006900139260000800208300001200216490000800228520043300236653003800669653004800707653001600755653003800771100001700809700001600826700001800842856010900860 2013 eng d a0026-897600aInteratomic coulombic decay in (HF)n,(n=2-3) clusters using CAP/EOM-CCSD method0 aInteratomic coulombic decay in HFnn23 clusters using CAPEOMCCSD  cNOV a669-6730 v1123 a

The equation-of-motion coupled-cluster method along with the complex absorbing potential has been applied to study the interatomic Coulombic decay mechanism in hydrogen-bonded clusters. We have applied this method to calculate the lifetime of the F 2s inner-valence ionised state of (HF)(n) (n = 2-3) clusters. The lifetime is found to be very short and decreases substantially with increasing the number of HF monomer.

10acomplex absorbing potential (CAP)10aequation-of-motion coupled-cluster (EOM-CC)10aHF clusters10ainteratomic Coulombic decay (ICD)1 aGhosh, Aryya1 aPal, Sourav1 aVaval, Nayana uhttps://library.ncl.res.in/content/interatomic-coulombic-decay-hfnn2-3-clusters-using-capeom-ccsd-method01546nas a2200169 4500008004100000022001400041245015900055210006900214260012500283300001100408490000800419520076700427100002001194700001801214700001601232856012801248 2013 eng d a0021-960600aLagrange multiplier approach for excited state properties through intermediate hamiltonian formulation of fock space multireference coupled-cluster theory0 aLagrange multiplier approach for excited state properties throug aCIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USAbAMER INST PHYSICScAUG a0741080 v1393 a

In this paper, we present a formulation based on Lagrange multiplier approach for efficient evaluation of excited state energy derivatives in Fock space coupled cluster theory within the intermediate Hamiltonian framework. The formulation is applied to derive the explicit generic expressions up to second order energy derivatives for [1, 1] sector of Fock space with singles and doubles approximation. Its advantage, efficiency, and interconnection in comparison to the Lagrange multiplier approach in traditional formulation of Fock space, which is built on the concept of Bloch equation based effective Hamiltonian, has been discussed. Computational strategy for their implementation has also been discussed in some detail. (C) 2013 AIP Publishing LLC.

1 aGupta, Jitendra1 aVaval, Nayana1 aPal, Sourav uhttps://library.ncl.res.in/content/lagrange-multiplier-approach-excited-state-properties-through-intermediate-hamiltonian-002065nas a2200169 4500008004100000022001400041245013600055210006900191260007100260300001400331490000600345520135700351100002701708700001801735700001601753856012601769 2013 eng d a1549-961800aPerformance of the EOMIP-CCSD(2) method for determining the structure and properties of doublet radicals: a benchmark investigation0 aPerformance of the EOMIPCCSD2 method for determining the structu a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcOCT a4313-43310 v93 a

We present a benchmark study on the performance of the EOMIP-CCSD(2) method for computation of structure and properties of doublet radicals. The EOMIP-CCSD(2) method is a second-order approximation to the standard EOMIP-CCSD method. By retaining the black box nature of the standard EOMIP-CCSD method and adding favorable N-5 scaling, the EOMIP-CCSD(2) method can become the method of choice for predicting the structure and spectroscopic properties of large doublet radicals. The EOMIP-CCSD(2) method overcomes the typical problems associated with the standard single reference ab initio treatment of doublet radicals. We compare our results for geometries and harmonic vibrational frequencies with those obtained using the standard EOMIP-CCSD method, as well as unrestricted Hartree-Fock (UHF)- and restricted open-shell Hartree-Fock (ROHF)-based single-reference coupled-cluster and second order many-body perturbation theory (MBPT(2)) methods. The effect of the basis set on the quality of the results has been studied using a hierarchy of Dunning's correlation-consistent aug-cc-pVXZ (X = D, T, Q) basis sets. Numerical results show that the EOMIP-CCSD(2) method, despite its N-5 scaling, gives better agreement with experimental results, compared to the UHF- and ROHF-based MBPT(2), as well as the single-reference coupled-cluster methods.

1 aDutta, Achintya, Kumar1 aVaval, Nayana1 aPal, Sourav uhttps://library.ncl.res.in/content/performance-eomip-ccsd2-method-determining-structure-and-properties-doublet-radicals-001670nas a2200169 4500008004100000022001400041245012200055210006900177260012500246300001100371490000800382520091700390100002701307700001601334700002101350856012901371 2013 eng d a0021-960600aPerturbative approximations to single and double spin flip equation of motion coupled cluster singles doubles methods0 aPerturbative approximations to single and double spin flip equat aCIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USAbAMER INST PHYSICScSEP a1241160 v1393 a

Spin flip equation of motion coupled cluster (EOM-SF-CC) can correctly treat situations involving electronic degeneracies or near degeneracies, e. g., bond breaking, di- and tri-radicals, etc. However, for large systems EOM-SF-CC (even in single and double excitations) is computationally prohibitively expensive. Therefore, earlier approximations to EOM-SF-CC methods such as spin flip configuration interaction singles with perturbative doubles (SF-CIS(D)) have been proposed. In this work, we present a new perturbative approximation to EOM-SF-CC, which has been found to be more accurate than SF-CIS(D). The capabilities, advantages, and timings of the new approach have been demonstrated considering the singlet-triplet gaps in di- and triradicals as well as bond breaking examples. The method is extended to double spin flip EOM-CC and its capabilities have been tested. (C) 2013 AIP Publishing LLC.

1 aDutta, Achintya, Kumar1 aPal, Sourav1 aGhosh, Debashree uhttps://library.ncl.res.in/content/perturbative-approximations-single-and-double-spin-flip-equation-motion-coupled-cluster-001375nas a2200181 4500008004100000022001400041245009200055210006900147260007300216300001200289490000800301520068400309100001800993700001801011700001601029700002301045856012501068 2013 eng d a0009-261400aPolarizability of few electron quantum dots: extended coupled-cluster response approach0 aPolarizability of few electron quantum dots extended coupledclus aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcJAN a263-2670 v5553 a

The dipole polarizability is studied for few electron quantum dots using extended coupled cluster linear response method (ECCLR). The polarizability of pure parabolic quantum dots depends only on the number of electrons and the parabolic confinement strength. We added impurity in a GAUSSIAN form to the external parabolic potential and used ECCLR to calculate polarizability. To examine the effect of external potential, we changed the parabolic confinement to square-well and repeated all calculations. We mainly looked at eigenvalue spectrum and charge density specially when the system shifts towards lower density regions. (C) 2012 Elsevier B. V. All rights reserved.

1 aHeidari, Ideh1 aVaval, Nayana1 aPal, Sourav1 aKanhere, Dilip, G. uhttps://library.ncl.res.in/content/polarizability-few-electron-quantum-dots-extended-coupled-cluster-response-approach-001813nas a2200253 4500008004100000022001400041245013200055210006900187260010200256300001400358490000800372520087400380653000601254653001901260653000801279653001201287653002701299653002601326653002401352100002501376700001901401700001601420856012301436 2013 eng d a0974-362600aRole of substituents on the reactivity and electron density profile of diimine ligands: a density functional theory based study0 aRole of substituents on the reactivity and electron density prof aC V RAMAN AVENUE, SADASHIVANAGAR, P B \#8005, BANGALORE 560 080, INDIAbINDIAN ACAD SCIENCEScSEP a1247-12580 v1253 a

In this paper, we study the reactivity of diimines like 2, 2(')-bipyridine, 1, l0-phenanthroline and 1, 2, 4-triazines using density-based reactivity descriptors. We discuss the enhancement or diminution in the reactivity of these ligands as a function of two substituent groups, namely methyl (-CH3) group and phenyl (-C6H5) group. The global reactivity descriptors explain the global affinity and philicity of these ligands, whereas the local softness depicts the particular site selectivity. The inter-molecular reactivity trends for the same systems are analysed through the philicity and group philicity indices. The sigma-donor character of these ligands is quantified with the help of electron density profile. In addition, the possible strength of interaction of these ligands with metal ions is supported with actual reaction energies of Ru-L complexes.

10a210a2 `-bipyridine10aDFT10adiimine10aReactivity descriptors10aRu-ligand interaction10asubstituent effects1 aKulkarni, Bhakti, S.1 aMishra, Deepti1 aPal, Sourav uhttps://library.ncl.res.in/content/role-substituents-reactivity-and-electron-density-profile-diimine-ligands-density-001566nas a2200169 4500008004100000022001400041245012000055210006900175260012500244300002300369490000800392520082000400100001701220700001601237700001801253856012501271 2013 eng d a0021-960600aStudy of interatomic coulombic decay of Ne(H2O)(n) (n=1,3) clusters using equation-of-motion coupled-cluster method0 aStudy of interatomic coulombic decay of NeH2On n13 clusters usin aCIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USAbAMER INST PHYSICScAUG aArticle No. 0641120 v1393 a

Interatomic Coulombic decay (ICD) is an efficient and ultrafast radiationless decay mechanism which can be initiated by removal of an electron from the inner-valence shell of an atom or molecule. Generally, the ICD mechanism is prevailed in weakly bound clusters. A very promising approach, known as CAP/EOM-CC, consists of the combination of complex absorbing potential (CAP) with the equation-of-motion coupled-cluster (EOM-CC) method, is applied for the first time to study the nature of the ICD mechanism. We have applied this technique to determine the lifetime of an auto-ionized, inner-valence excited state of the NeH2O, Ne(H2O)(2), and Ne(H2O)(3) systems. The lifetime is found to be very short and decreases significantly with the number of neighboring water molecules. (C) 2013 AIP Publishing LLC.

1 aGhosh, Aryya1 aPal, Sourav1 aVaval, Nayana uhttps://library.ncl.res.in/content/study-interatomic-coulombic-decay-neh2on-n13-clusters-using-equation-motion-coupled-002311nas a2200253 4500008004100000022001400041245015100055210006900206260009200275300001200367490000700379520138900386653001101775653000901786653000901795653000901804653002001813653001401833100001901847700001701866700002701883700001601910856013101926 2013 eng d a0892-702200aUnderstanding the orientation of water molecules around the phosphate and attached functional groups in a phospholipid molecule: a DFT-based study0 aUnderstanding the orientation of water molecules around the phos a4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLANDbTAYLOR & FRANCIS LTDcOCT a937-9550 v393 a

The adsorption of water molecules around a polar region (in particular around the phosphate moiety) in the phospholipid molecules is studied in this work. Phospholipid molecules with different functional groups are known to respond differently to the water molecules. Hence, we attempt to study the adsorption of water molecules around the phosphate group as a consequence of the change of functional group attached to the phosphate group, viz. phosphatidyl ethanolamine (PE), phosphatidyl choline (PC) and phosphatidyl glycerol (PG). As the latter is anionic in nature, the charge is compensated by Na+ counterion. Up to seven water molecules are adsorbed around the phosphate groups in model systems mimicking phospholipid molecule. The corresponding changes in the structural and electronic aspects are analysed. The significant difference between the PE and PC model systems is the formation of clathrate-like structure in the latter. Itisnoticed that as the number of water molecules increases to seven, both the hydrogen atoms in the water molecule participate in hydrogen bonding. However, in the PG model system, the charge-compensating counterion prevents the water molecule to form clathrate-like structures. The adsorption sites for water molecules are validated by density functional theory-based reactivity descriptors, viz. Fukui functions in the PE model system.

10acHelpG10aDMPC10aDMPE10aDMPG10aFukui functions10aHydration1 aMishra, Deepti1 aDas, Susanta1 aKrishnamurthy, Sailaja1 aPal, Sourav uhttps://library.ncl.res.in/content/understanding-orientation-water-molecules-around-phosphate-and-attached-functional-groups-001795nas a2200169 4500008004100000022001400041245021300055210006900268260007100337300001400408490000800422520102600430100001701456700001601473700002601489856011001515 2013 eng d a1089-563900aUnderstanding the site selectivity in small-sized neutral and charged AI(n) (4 <= n <= 7) clusters using density functional theory based reactivity descriptors: a validation study on water molecule adsorption0 aUnderstanding the site selectivity in smallsized neutral and cha a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcSEP a8691-87020 v1173 a

Aluminum clusters are now technologically important due to their high catalytic activity. Our present study on the small-sized aluminum clusters applies density functional theory (DFT)-based reactivity descriptors to identify potential sites for adsorption and eventual chemical reaction. Depending on symmetry, susceptibility of various type of reactive sites within a cluster toward an impending electrophilic and/or nucleophilic attack is predicted using the reactivity descriptors. In addition, the study devises general rules as to how the size, shape, and charge of the cluster influences the number of available sites for an electrophilic and/or nucleophilic attack. The predictions by reactivity descriptors are validated by performing an explicit adsorption of water molecule on Al clusters with four atoms. The adsorption studies demonstrate that the most stable water-luster complex is obtained when the molecule is adsorbed through an oxygen atom on the site with the highest relative electrophilicity.

1 aDas, Susanta1 aPal, Sourav1 aKrishnamurty, Sailaja uhttps://library.ncl.res.in/content/understanding-site-selectivity-small-sized-neutral-and-charged-ain-4-001629nas a2200277 4500008004100000022001400041245010600055210006900161260007300230300001200303490000800315520066700323653000800990653001300998653002301011653002401034100002501058700002101083700002001104700001901124700001601143700001701159700002001176700002501196856013001221 2014 eng d a1381-116900a1,8-Diazabicyclo[5.4.0]undec-7-ene (DBU): a highly efficient catalyst in glycerol carbonate synthesis0 a18Diazabicyclo540undec7ene DBU a highly efficient catalyst in gl aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcSEP a144-1490 v3913 a

Transesterification of dimethyl carbonate (DMC) with glycerol (GLY) was investigated using various amines as catalysts. Amidines like 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) and 1,5-diazabicyclo[4.3.0]non-5-ene (DBN) were found to be the best catalysts for this reaction. Best results: 98% conversion of GLY with 96% selectivity to GC (TON: 9408), were obtained with DBU as a catalyst. Effect of various reaction conditions on activity and selectivity were investigated using DBU as catalyst. The mechanism of the reaction was investigated with the help of H-1, C-13 and N-15 NMR analysis and OFT calculations. (C) 2014 Elsevier B.V. All rights reserved.

10aDBU10aGlycerol10aGlycerol carbonate10atransesterification1 aMunshi, Mudassir, K.1 aGade, Swapna, M.1 aMane, Manoj, V.1 aMishra, Deepti1 aPal, Sourav1 aVanka, Kumar1 aRane, Vilas, H.1 aKelkar, Ashutosh, A. uhttps://library.ncl.res.in/content/18-diazabicyclo540undec-7-ene-dbu-highly-efficient-catalyst-glycerol-carbonate-synthesis-000592nas a2200133 4500008004100000022001400041245008300055210006900138260007900207300003100286490000800317100001600325856011700341 2014 eng d a0065-772700aComplex absorbing potential based coupled-cluster methods to metastable states0 aComplex absorbing potential based coupledcluster methods to meta a1155 16th ST, NW, Washington, DC 20036 USAbAmerican Chemical SocietycAUG aMeeting Abstract: 504-COMP0 v2481 aPal, Sourav uhttps://library.ncl.res.in/content/complex-absorbing-potential-based-coupled-cluster-methods-metastable-states-001465nas a2200181 4500008004100000022001400041245012500055210006900180260008700249300002300336490000800359520070900367100001701076700001801093700001601111700002501127856013101152 2014 eng d a0021-960600aComplex absorbing potential based equation-of-motion coupled cluster method for the potential energy curve of CO2- anion0 aComplex absorbing potential based equationofmotion coupled clust a1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USAbAMER INST PHYSICScOCT aArticle No. 1641130 v1413 a

The equation-of-motion coupled cluster method employing the complex absorbing potential has been used to investigate the low energy electron scattering by CO2. We have studied the potential energy curve for the (2)Pi(u) resonance states of CO2- upon bending as well as symmetric and asymmetric stretching of the molecule. Specifically, we have stretched the C-O bond length from 1.1 angstrom to 1.5 angstrom and the bending angles are changed between 180 degrees and 132 degrees. Upon bending, the low energy (2)Pi(u) resonance state is split into two components, i.e., (2)A(1), B-2(1) due to the Renner-Teller effect, which behave differently as the molecule is bent. (c) 2014 AIP Publishing LLC.

1 aGhosh, Aryya1 aVaval, Nayana1 aPal, Sourav1 aBartlett, Rodney, J. uhttps://library.ncl.res.in/content/complex-absorbing-potential-based-equation-motion-coupled-cluster-method-potential-energy-001941nas a2200241 4500008004100000022001400041245011400055210006900169260005700238300000900295490000800304520105600312653002401368653003601392653001101428653002401439653002101463100002101484700002201505700002601527700001601553856013001569 2014 eng d a1432-881X00aComputational investigation on the catalytic activity of Rh-6 and Rh4Ru2 clusters towards methanol activation0 aComputational investigation on the catalytic activity of Rh6 and a233 SPRING ST, NEW YORK, NY 10013 USAbSPRINGERcDEC a15970 v1343 a

Catalysis of molecular activation of small molecules through scission of strong chemical bonds is one of the major challenges faced by chemists. More specifically, activation of the strong C-H and O-H bonds of various alcohols, especially methanol, is one of the various important intermediate steps of key organic reactions. Our present work explores a suitable metal cluster catalyst towards methanol dissociation. In particular, we have examined the effect of ruthenium doping (Rh:Ru = 2:1) on the catalytic activity of Rh-6 cluster towards methanol dissociation. Density functional theory-based calculations illustrate two competitive pathways for methanol dissociation, which are via O-H and C-H bond breaking. Both the pathways are found to be energetically favourable in the presence of bimetallic and mono-metallic clusters. Importantly, energy barrier for O-H bond dissociation reduces considerably in doped cluster as compared to pure Rh-6 cluster and is smaller than the values reported for a number of other small metallic clusters.

10aBimetallic Clusters10aDensity Functional Theory (DFT)10aDoping10aMethanol Activation10aRhodium Clusters1 aGhatak, Kamalika1 aSengupta, Turbasu1 aKrishnamurty, Sailaja1 aPal, Sourav uhttps://library.ncl.res.in/content/computational-investigation-catalytic-activity-rh-6-and-rh4ru2-clusters-towards-methanol-002012nas a2200169 4500008004100000022001400041245007600055210006900131260007100200300001600271490000800287520137800295100001701673700001601690700002601706856011001732 2014 eng d a1932-744700aDinitrogen activation by silicon and phosphorus doped aluminum clusters0 aDinitrogen activation by silicon and phosphorus doped aluminum c a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcAUG a19869-198780 v1183 a

N-2 reduction is crucial for life, and very few catalysts are currently available to carry out this process at ambient temperature and pressure. In the present work, density functional theory based calculations reveal doped aluminum clusters to be highly reactive toward molecular nitrogen and hence are prospective materials for its activation at low temperatures. Calculations on silicon and phosphorus doped aluminum clusters with 5-8 atoms demonstrate an enhanced N-2 activation with respect to their pristine ground state and high energy counterparts. This increased efficiency of N-2 activation by doped ground state Al clusters is corroborated by an increment of the N N bond length, a red shift in N N bond stretching frequency, and adsorption energy (E-ad). Ab initio molecular-dynamics simulations demonstrate consequential efficiency of doped clusters toward dinitrogen activation at finite temperature. The ability of doped clusters toward activation of molecular nitrogen is site and shape sensitive. In short, this theoretical study highlights the critical role of doping foreign impurities for future endeavors in the design of cost-effective and efficient catalysts for N-2 activation at ambient temperatures. This observation may spur further studies in the field of aluminum nanocatalysis by doping silicon and phosphorus atom in aluminum clusters.

1 aDas, Susanta1 aPal, Sourav1 aKrishnamurty, Sailaja uhttps://library.ncl.res.in/content/dinitrogen-activation-silicon-and-phosphorus-doped-aluminum-clusters-002006nas a2200169 4500008004100000022001400041245008700055210006900142260000900211300001400220490000800234520142600242100001701668700002601685700001601711856010901727 2014 eng d a1932-744700aEffect of silicon doping on the reactivity and catalytic activity of gold clusters0 aEffect of silicon doping on the reactivity and catalytic activit cAPR  a7501-75070 v1183 a

Doping is known to be an excellent and simple way of catalyst design. Although notable progress has been made in understanding the reactivity and catalytic activity of gas-phase and supported gold clusters, very few studies have been carried out on the doped gold clusters. In the present work, we have carried out density functional theory calculations to investigate the effect of silicon doping on the reactivity and catalytic activity of gold nanoclusters. The present work particularly focuses on the adsorption and activation of molecular oxygen on the pristine and silicon-doped gold clusters. The results confirm that the silicon-doped Au7Si cluster shows considerable binding and activation of the O-2 molecule in comparison to the pristine Au-8 cluster as reflected in the relevant geometrical parameters (O-O and Au-O bond lengths) and O-O stretching frequency. However, silicon doping has no contrasting effect on the reactivity and catalytic activity of the Au-7 cluster. In addition to the stronger binding and activation of the O-2 molecule, the doped Au7Si cluster leads to a significant reduction in the activation barrier (0.57 eV) for the environmentally important CO oxidation reaction in contrast to the catalytically inactive pristine Au-8 cluster (1.22 eV). Thus, our results highlight the critical role of doping foreign impurities for future endeavors in the field of gold nanocatalysis.

1 aManzoor, Dar1 aKrishnamurty, Sailaja1 aPal, Sourav uhttps://library.ncl.res.in/content/effect-silicon-doping-reactivity-and-catalytic-activity-gold-clusters01607nas a2200217 4500008004100000022001400041245012100055210006900176260006700245300001400312490000800326520075300334653003301087653001501120653002401135653004001159100002701199700001801226700001601244856012901260 2014 eng d a0020-760800aElectronic transition dipole moment: a semi-biorthogonal approach within valence universal coupled cluster framework0 aElectronic transition dipole moment a semibiorthogonal approach  a111 RIVER ST, HOBOKEN 07030-5774, NJ USAbWILEY-BLACKWELLcSEP a1212-12190 v1143 a

Electronic dipole strengths (square of transition moments) and oscillator strengths are evaluated for various transitions, arising from the ground state to a few valence excited states. Parallel to two other methods of calculating the dipole strength within the Fock-space multireference coupled cluster framework, a new semi-biorthogonal approach is formulated and implemented in this article. This semi-biorthogonal approach can evaluate dipole strengths at a lower computational effort than the biorthogonal approach without compromising on the accuracy. This new method is compared and tested against the previously developed expectation value and biorthogonal approach for various molecular transitions. (C) 2014 Wiley Periodicals, Inc.

10aelectronic transition dipole10aFock-space10aoscillator strength10asemi-biorthogonal expectation value1 aBhattacharya, Debarati1 aVaval, Nayana1 aPal, Sourav uhttps://library.ncl.res.in/content/electronic-transition-dipole-moment-semi-biorthogonal-approach-within-valence-universal-001803nas a2200229 4500008004100000022001400041245009900055210006900154260011000223300001300333490000700346520091800353653002501271653003601296653001801332653001901350653002001369653002601389100001701415700001601432856012501448 2014 eng d a0376-471000aEnhanced interaction of molecular oxygen with amino acid complexes of silver and gold clusters0 aEnhanced interaction of molecular oxygen with amino acid complex aDR K S KRISHNAN MARG, PUSA CAMPUS, NEW DELHI 110 012, INDIAbNATL INST SCIENCE COMMUNICATION-NISCAIRcAUG a996-10000 v533 a

Density functional theory calculations have been carried out to study the effect of amino acid adsorption on the reactivity of silver and gold clusters with molecular oxygen. It is found that the amino acids glycine and alanine form stable complexes with both Ag-4 and Au-4 clusters. However, the extent of interaction is more in the case of the Au-4 cluster, as reflected from the increase in binding energy in the amino acid Au-4 complexes. Our results confirm that the adsorption of amino acids glycine and alanine enhances the reactivity of Ag-4 and Au-4 clusters towards O-2 molecule. The enhanced reactivity of O-2 molecule towards the amino acid metal cluster complexes is manifested by an increase in the O-2 binding energy and a decrease in the M-O (M = Ag, Au) bond length. Moreover, it is found that the co-adsorption of amino acids and O-2 molecule on the Ag-4 and Au-4 clusters is cooperative.

10aAmino acid complexes10aDensity functional calculations10aGold clusters10aMetal clusters10aSilver clusters10aTheoretical chemistry1 aManzoor, Dar1 aPal, Sourav uhttps://library.ncl.res.in/content/enhanced-interaction-molecular-oxygen-amino-acid-complexes-silver-and-gold-clusters-001513nas a2200181 4500008004100000022001400041245005700055210005500112260008700167300001100254490000800265520088000273100002701153700002801180700001801208700001601226856008901242 2014 eng d a0021-960600aGround state of naphthyl cation: singlet or triplet?0 aGround state of naphthyl cation singlet or triplet a1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USAbAMER INST PHYSICScMAR a1143120 v1403 a

We present a benchmark theoretical investigation on the electronic structure and singlet- triplet(ST) gap of 1- and 2-naphthyl cations using the CCSD(T) method. Our calculations reveal that the ground states of both the naphthyl cations are singlet, contrary to the results obtained by DFT/B3LYP calculations reported in previous theoretical studies. However, the triplet states obtained in the two structural isomers of naphthyl cation are completely different. The triplet state in 1-naphthyl cation is (pi,sigma) type, whereas in 2-naphthyl cation it is (pi,sigma) type, The S-T gaps in naphthyl cations and the relative stability ordering of the singlet and the triplet states are highly sensitive to the basis set quality as well as level of correlation, and demand for inclusion of perturbative triples in the coupled-cluster ansatz. (c) 2014 AIP Publishing LLC.

1 aDutta, Achintya, Kumar1 aManohar, Prashant, Uday1 aVaval, Nayana1 aPal, Sourav uhttps://library.ncl.res.in/content/ground-state-naphthyl-cation-singlet-or-triplet-001933nas a2200157 4500008004100000022001400041245011000055210006900165260007100234300001600305490000800321520128500329100001701614700001601631856012801647 2014 eng d a1932-744700aHydrogen atom chemisorbed gold clusters as highly active catalysts for oxygen activation and co oxidation0 aHydrogen atom chemisorbed gold clusters as highly active catalys a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcDEC a30057-300620 v1183 a

Using oxygen activation and carbon monoxide oxidation as a probe, we have carried out density functional theory (DFT) calculations to investigate the effect of hydrogen atom chemisorption on the reactivity and catalytic activity of gold nanoclusters. In the present work, we particularly focus on the closed shell neutral Au-n (n = 2, 4, 6, 8) gold clusters which are reported to be chemically inert and catalytically less active. The results confirm that the hydrogen atom chemisorption activates the inert clusters, thereby leading to enhanced binding and activation of the O-2 molecule. A significant amount of increase in the O-O and decrease in the Au-O bond lengths together with a pertinent red shift in the O-O stretching frequencies clearly indicates the stronger binding and activation of oxygen molecule in the case of AunH clusters. Further, our results reveal that the hydrogen atom chemisorbed gold clusters are catalytically more active with low activation barriers for the CO oxidation reaction compared to the parent less active closed shell gold clusters. Thus, in short the current theoretical observation provides key inputs for enhancing the reactivity and catalytic activity of inert gold clusters through the adsorption of a small atom or a molecule.

1 aManzoor, Dar1 aPal, Sourav uhttps://library.ncl.res.in/content/hydrogen-atom-chemisorbed-gold-clusters-highly-active-catalysts-oxygen-activation-and-co01630nas a2200181 4500008004100000022001400041245010700055210006900162260007100231300001400302490000700316520092200323100002701245700002001272700001801292700001601310856012201326 2014 eng d a1549-961800aIntermediate hamiltonian fock space multireference coupled cluster approach to core excitation spectra0 aIntermediate hamiltonian fock space multireference coupled clust a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcSEP a3656-36680 v103 a

The Fock space multireference coupled cluster (FSMRCC) method provides an efficient approach for the direct calculation of excitation energies. In intermediate Hamiltonian (IH-FSMRCC) formulation, the method is free from intruder state problems and associated convergence difficulties, even with a large model space. In this paper, we demonstrate that the IH-FSMRCC method with suitably chosen model space can be used for the accurate description of core excitation spectra of molecules, and our results are in excellent agreement with the experimental values. We have investigated the effect of choice of model space on the computed results. Unlike the equation-of-motion (EOM)-based method, the IH-FSMRCC does not require any special technique for convergence and in singles and doubles approximation gives a performance comparable to that of the standard EOMEE-CCSD method, even better in some of the cases.

1 aDutta, Achintya, Kumar1 aGupta, Jitendra1 aVaval, Nayana1 aPal, Sourav uhttps://library.ncl.res.in/content/intermediate-hamiltonian-fock-space-multireference-coupled-cluster-approach-core-001841nas a2200265 4500008004100000022001400041245009000055210006900145260007900214300000800293490000700301520090900308653002601217653002501243653002401268653002201292653002501314653002201339653001601361100002001377700002401397700001901421700001601440856011901456 2014 eng d a1093-326300aMolecular recognition pattern of cytotoxic alkaloid vinblastine with multiple targets0 aMolecular recognition pattern of cytotoxic alkaloid vinblastine  a360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USAbELSEVIER SCIENCE INCcNOV a1-90 v543 a

Vinblastine (VLB), a cytotoxic alkaloid is used extensively against various cancer types and the crystal structure of its tubulin complex is already known. Multitarget affinity of vinblastine has been investigated and the nature of binding with biological receptors namely, duplex DNA and Human serum albumin (HSA) has been compared to the binding characteristics of its known complex with natural high affinity receptor tubulin using molecular docking and QM-MM calculations. VLB is found to interact with DNA as well as HSA protein, though, with weaker affinity as compared to tubulin. Analysis of various docked complexes revealed that the H-bonds and cation-pi bonds do not have significant contribution to the binding interactions and despite its large size, VLB remains in relaxed conformation and fits in the hydrophobic regions on the receptors. (C) 2014 Elsevier Inc. All rights reserved.

10aDrug-DNA interactions10aDrug-protein binding10aHuman serum albumin10aMolecular docking10aMultitarget affinity10aQM-MM calculation10aVinblastine1 aPandya, Prateek1 aAgarwal, Lokesh, Kr1 aGupta, Neelima1 aPal, Sourav uhttps://library.ncl.res.in/content/molecular-recognition-pattern-cytotoxic-alkaloid-vinblastine-multiple-targets-001469nas a2200193 4500008004100000022001400041245010200055210006900157260007100226300001400297490000700311520073000318100002701048700002001075700002001095700001801115700001601133856012601149 2014 eng d a1549-961800aPartitioned EOMEA-MBPT(2): an efficient N-5 scaling method for calculation of electron affinities0 aPartitioned EOMEAMBPT2 an efficient N5 scaling method for calcul a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcAPR a1923-19330 v103 a

We present an N-5 scaling modification to the standard EOMEA-CCSD method, based on the matrix partitioning technique and perturbative approximations. The method has lower computational scaling and smaller storage requirements than the standard EOMEA-CCSD method and, therefore, can be used to calculate electron affinities of large molecules and clusters. The performance and capabilities of the new method have been benchmarked with the standard EOMEA-CCSD method, for a test set of 20 small molecules, and the average absolute deviation is only 0.03 eV. The method is further used to investigate electron affinities of DNA and RNA nucleobases, and the results are in excellent agreement with the experimental values.

1 aDutta, Achintya, Kumar1 aGupta, Jitendra1 aPathak, Himadri1 aVaval, Nayana1 aPal, Sourav uhttps://library.ncl.res.in/content/partitioned-eomea-mbpt2-efficient-n-5-scaling-method-calculation-electron-affinities-002356nas a2200265 4500008004100000022001400041245016800055210006900223260010600292300001400398490000700412520129400419653003001713653002001743653001701763653002301780653004101803100002001844700001701864700002401881700001601905700001601921700002201937856013101959 2014 eng d a0360-319900aPhotoelectrochemical splitting of water with nanocrystalline Zn1-xMnxO thin films: first-principle DFT computations supporting the systematic experimental endeavor0 aPhotoelectrochemical splitting of water with nanocrystalline Zn1 aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLANDbPERGAMON-ELSEVIER SCIENCE LTDcMAR a3637-36480 v393 a

Photoelectrochemical splitting of water with nanocrystalline Zn1-xMnxO thin films was investigated. ZnO thin films with 1, 3, 5 and 7% at. Mn incorporation were synthesized by sol gel method and characterized by X-Ray Diffraction (XRD) analysis, Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), X-ray Photoelectron spectroscopy (XPS), High Resolution Transmission Electron Microscopy (HR-TEM) and UV-Vis spectroscopy. Mn incorporation coupled with variation in sintering temperature led to significant microstructural changes, which tentatively influenced the magnitude of optical absorption and charge carrier mobility, thereby impacting the performance of such systems towards photoelectrochemical splitting of water. Electronic structure computations based on first principle density functional theory (DFT) revealed electronic states of Mn being responsible for the marginally recorded red shift in bandgap energy. Photoelectrochemical measurements using thin films of 1% at. Mn:ZnO sintered at 600 degrees C yielded 3 times enhanced photocurrent at zero bias due to improved optical absorption. Plausible explanations for the effect have also been offered. Copyright (C) 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

10aDensity functional theory10aHydrogen energy10aMn doped ZnO10aOptical properties10aPhotoelectrochemical water splitting1 aSharma, Vidhika1 aDixit, Mudit1 aSatsangi, Vibha, R.1 aDass, Sahab1 aPal, Sourav1 aShrivastav, Rohit uhttps://library.ncl.res.in/content/photoelectrochemical-splitting-water-nanocrystalline-zn1-xmnxo-thin-films-first-principle-001755nas a2200193 4500008004100000022001400041245010300055210006900158260000900227300001100236490000700247520108800254100002001342700001801362700001601380700001801396700001601414856013101430 2014 eng d a2469-992600aRelativistic equation-of-motion coupled-cluster method: application to closed-shell atomic systems0 aRelativistic equationofmotion coupledcluster method application  cAPR  a0425100 v893 a

We report our successful implementation of the relativistic equation-of-motion coupled-cluster (EOMCC) method. This method is employed to compute the principal ionization potentials (IPs) of closed-shell rare-gas atoms, He-like ions, Be-like ions, along with Na+, Al+, K+, Be, andMg. Four-component Dirac spinors are used in the calculations, and the one-and two-electron integrals are evaluated using the Dirac-Coulomb Hamiltonian. Our results are in excellent agreement with available measurements, which are taken from the National Institute of Science and Technology database. The accuracies of the calculations are estimated to be within one half of a percent for He-like and Be-like ions and 1% for the heavier systems. We also present results using the second-order many-body perturbation theory and random-phase approximation in the EOMCC framework. These results are compared with those of EOMCC at the level of single and double excitations in order to assess the role of the electron correlation effects in the intermediate schemes considered in our calculations.

1 aPathak, Himadri1 aSahoo, B., K.1 aDas, B., P.1 aVaval, Nayana1 aPal, Sourav uhttps://library.ncl.res.in/content/relativistic-equation-motion-coupled-cluster-method-application-closed-shell-atomic-systems00680nas a2200181 4500008004100000245011800041210006900159260000800228300002300236490000700259100002000266700001700286700001800303700001600321700001800337700001600355856012700371 2014 eng d00aRelativistic equation-of-motion coupled-cluster method for the double-ionization potentials of closed-shell atoms0 aRelativistic equationofmotion coupledcluster method for the doub cJUL aArticle No. 0105010 v901 aPathak, Himadri1 aGhosh, Aryya1 aSahoo, B., K.1 aDas, B., P.1 aVaval, Nayana1 aPal, Sourav uhttps://library.ncl.res.in/content/relativistic-equation-motion-coupled-cluster-method-double-ionization-potentials-closed01580nas a2200193 4500008004100000022001400041245011200055210006900167260007900236300002300315490000700338520082300345100002001168700001801188700002201206700001801228700001601246856012401262 2014 eng d a1050-294700aRelativistic equation-of-motion coupled-cluster method for the ionization problem: application to molecules0 aRelativistic equationofmotion coupledcluster method for the ioni aONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USAbAMER PHYSICAL SOCcDEC aArticle No. 0625010 v903 a

We report the implementation of the four-component spinor relativistic equation-of-motion (EOM) coupled-cluster method within the single- and double-excitation approximation to calculate the ionization potential of molecules. We have applied this method to calculate vertical ionization potentials of the molecules XH (X = F, Cl, Br, I) along with Cl-2 and Br-2 in their closed-shell configuration. We have also presented intermediate results using the second-order many-body perturbation-theory level in the EOM framework to understand the role of electron correlation. All the calculated values are compared with the available experimental results. Our results are found to be in good agreement with sophisticated experiments, and relative deviation of less than 1% is achieved for all the considered systems.

1 aPathak, Himadri1 aSasmal, Sudip1 aNayak, Malaya, K.1 aVaval, Nayana1 aPal, Sourav uhttps://library.ncl.res.in/content/relativistic-equation-motion-coupled-cluster-method-ionization-problem-application-002123nas a2200205 4500008004100000022001400041245011700055210006900172260008100241300001100322490000700333520133300340653002401673653001601697653002401713100001901737700001801756700001601774856012701790 2014 eng d a0953-407500aRelativistic spectroscopy of plasma-embedded Li-like systems with screening effects in two-body Debye potentials0 aRelativistic spectroscopy of plasmaembedded Lilike systems with  aTEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLANDbIOP PUBLISHING LTDcSEP a1757010 v473 a

The spectroscopic properties of Li atoms and Li-like Ca and Ti ions in the plasma environment are investigated using a relativistic coupled-cluster (RCC) method. Assuming that the plasma is of low density and very hot, we consider the Debye model with two approximations to account for the screening effects: (i) in the nuclear potential alone and (ii) in both the nuclear and the electron-electron interaction potentials. Also, calculations for the energies and the lifetimes of the atomic states are carried out for plasma-free systems to check their accuracy, after which they are investigated in the plasma environment. It is observed that screenings in the electron-electron interaction potentials stabilize the systems more than when the screenings are present only in the nuclear potential. Similarly, the blue and red shifts in the Delta n = 0 and Delta n not equal 0 transition lines (with the principal quantum number n) of the Li-like ions observed in the (i) approximation are altered in the (ii) approximation. The level crossings among the energy levels are observed for large screening effects and are found to be prominent in the states of higher orbital angular momentum. The lifetimes of many low-lying states of the allowed transitions are estimated by considering different plasma screening strengths.

10aatomic Spectroscopy10aDebye model10arelativistic method1 aDas, Madhulita1 aSahoo, B., K.1 aPal, Sourav uhttps://library.ncl.res.in/content/relativistic-spectroscopy-plasma-embedded-li-systems-screening-effects-two-body-debye-001852nas a2200181 4500008004100000022001400041245011900055210006900174260007100243300001400314490000800328520112900336100002701465700001701492700001801509700001601527856012701543 2014 eng d a1089-563900aStructure, stability, and properties of the trans peroxo nitrate radical: the importance of nondynamic correlation0 aStructure stability and properties of the trans peroxo nitrate r a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcFEB a1350-13620 v1183 a

We report a comparative single-reference and multireference coupled-cluster investigation on the structure, potential energy surface, and IR spectroscopic properties of the trans peroxo nitrate radical, one of the key intermediates in stratospheric NOx chemistry. The previous single-reference ab initio studies predicted an unbound structure for the trans peroxo nitrate radical. However, our Fock space multireference coupled-cluster calculation confirms a bound structure for the trans peroxo nitrate radical, in accordance with the experimental results reported earlier. Further, the analysis of the potential energy surface in FSMRCC method indicates a well-behaved minima, contrary to the shallow minima predicted by the single-reference coupled-cluster method. The harmonic force field analysis, of various possible isomers of peroxo nitrate also reveals that only the trans structure leads to the experimentally observed IR peak at 1840 cm(-1). The present study highlights the critical importance of nondynamic correlation in predicting the structure and properties of high-energy stratospheric NOx radicals.

1 aDutta, Achintya, Kumar1 aDar, Manzoor1 aVaval, Nayana1 aPal, Sourav uhttps://library.ncl.res.in/content/structure-stability-and-properties-trans-peroxo-nitrate-radical-importance-nondynamic-001609nas a2200193 4500008004100000022001400041245012300055210006900178260008700247300001100334490000800345520084000353100001801193700002001211700002201231700001801253700001601271856012801287 2015 eng d a0021-960600aCalculation of P,T-odd interaction constant of PbF using Z-vector method in the relativistic coupled-cluster framework0 aCalculation of PTodd interaction constant of PbF using Zvector m a1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USAbAMER INST PHYSICScAUG a0841190 v1433 a

The effective electric field experienced by the unpaired electron in the ground state of PbF, which is a potential candidate in the search of electron electric dipole moment due to some special characteristics, is calculated using Z-vector method in the coupled cluster single-and double-excitation approximation with four component Dirac spinor. This is an important quantity to set the upper bound limit of the electron electric dipole moment. Further, we have calculated molecular dipole moment and parallel magnetic hyperfine structure constant (A(parallel to)) of Pb-207 in PbF to test the accuracy of the wavefunction obtained in the Z-vector method. The outcome of our calculations clearly suggests that the core electrons have significant contribution to the ``atom in compound'' properties. (C) 2015 AIP Publishing LLC.

1 aSasmal, Sudip1 aPathak, Himadri1 aNayak, Malaya, K.1 aVaval, Nayana1 aPal, Sourav uhttps://library.ncl.res.in/content/calculation-pt-odd-interaction-constant-pbf-using-z-vector-method-relativistic-coupled-102516nas a2200229 4500008004100000022001400041245011300055210006900168260006700237300001200304490000700316520160600323653002801929653002501957653003601982653003202018653004102050100002302091700001602114700002902130856012702159 2015 eng d a0952-349900aComputational strategies for understanding the nature of interaction in dioxin imprinted nanoporous trappers0 aComputational strategies for understanding the nature of interac a111 RIVER ST, HOBOKEN 07030-5774, NJ USAbWILEY-BLACKWELLcJUL a427-4370 v283 a

A new computational model capable of understanding the nature of interactions in signature complexes formed between the template(2,3,7,8-tetrachlorodibenzo-p dioxin (TCDD)) and the functional monomers (methacrylic acid (MAA)) using density functional theory (DFT) has been designed. The polymer precursors were optimized for geometries in polymerization media, computing the interaction energies between template molecules and functional monomers of transient pre-polymerized complexes (PPC), and structural and vibrational properties reference to theoretical infrared spectra were computed using DFT of B3LYP/6 311+G(d,p) hybrid functional method. Atom in molecule theory was used to analyze the hydrogen-bonding characteristics of PPC of MAA-TCDD. Considering the theoretical titrations conducted in a virtual solvent box, it was found that the 1:4 molar ratio was required to form the most stable PPC in a given solvent system. The electron density plots indicate strong hydrogen bonding as shown by the 2pz dominant highest occupied molecular orbital (HOMO) character that could be the preferable sites of binding for target molecule, TCDD. Considering HOMO approach, the active adsorption sites in molecularly imprinted polymer was modeled to get insight on molecular recognition property for targeted molecule, TCDD. The proposed computational protocol is simple, accurate, and novel to design the polymer and is useful to predict the properties of polymer systems than the conventional theoretical analysis of template-monomer interactions. Copyright (c) 2015 John Wiley & Sons, Ltd.

10acarcinogenic pollutants10acomputer simulations10aDensity Functional Theory (DFT)10aintermolecular interactions10aMolecularly Imprinted Polymers (MIP)1 aKhan, Muntazir, S.1 aPal, Sourav1 aKrupadam, Reddithota, J. uhttps://library.ncl.res.in/content/computational-strategies-understanding-nature-interaction-dioxin-imprinted-nanoporous-002323nas a2200217 4500008004100000022001400041245007500055210006900130260006700199300001200266490000800278520158100286653001801867653002201885653001001907100002701917700002201944700001801966700001601984856010502000 2015 eng d a0020-760800aElectron attachment to DNA and RNA nucleobases: an EOMCC investigation0 aElectron attachment to DNA and RNA nucleobases an EOMCC investig a111 RIVER ST, HOBOKEN 07030-5774, NJ USAbWILEY-BLACKWELLcJUN a753-7640 v1153 a

We report a benchmark theoretical investigation of both vertical and adiabatic electron affinities of DNA and RNA nucleobases: adenine, guanine, cytosine, thymine, and uracil using equation of motion coupled cluster method. The vertical electron affinity (VEA) values of the first five states of the DNA and RNA nucleobases are computed. It is observed that the first electron attached state is energetically accessible in gas phase. Furthermore, an analysis of the natural orbitals exhibits that the first electron attached states of uracil and thymine are valence-bound in nature and undergo significant structural changes on attachment of an extra electron, which reflects in the deviation of the adiabatic electron affinity (AEA) than that of the vertical ones. Conversely, the first electron attached states of cytosine, adenine, and guanine are in the category of dipole-bound anions. Their structure, by and large, remain unaffected on attachment of an extra electron, which is evident from the observed small difference between the AEA and VEA values. VEA and AEA values of all the DNA and RNA nucleobases are found to be negative, which implies that the first electron attached states are not stable rather quasi bound. The results of all previous theoretical calculations are out of track and shows large deviation with respect to the experimentally measured values, whereas, our results are found to be in good agreement. Therefore, our computed values can be used as a reliable standard to calibrate new theoretical methods. (c) 2015 Wiley Periodicals, Inc.

10aDNA-RNA bases10aelectron affinity10aEOMCC1 aDutta, Achintya, Kumar1 aSengupta, Turbasu1 aVaval, Nayana1 aPal, Sourav uhttps://library.ncl.res.in/content/electron-attachment-dna-and-rna-nucleobases-eomcc-investigation-001653nas a2200169 4500008004100000022001400041245008500055210006900140260007100209300001400280490000700294520101700301100002701318700001801345700001601363856010401379 2015 eng d a1549-961800aEOMIP-CCSD(2)*: an efficient method for the calculation of ionization potentials0 aEOMIPCCSD2 an efficient method for the calculation of ionization a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcJUN a2461-24720 v113 a

A new approximation within the domain of EOMIP-CC method is proposed. The proposed scheme is based on the perturbative truncation of the similarity transformed effective Hamiltonian matrix. We call it the EOMIP-CCSD(2)* method, which scales as noniterative N-6 and its storage requirement is very less, compared to the conventional EOMIP-CCSD method. The existing EOMIP-CCSD(2) method has a tendency to overestimate the ionization potential (IP) values. On the other hand, our new strategy corrects for the problem of such an overestimation, which is evident from the excellent agreement achieved with the experimental values. Furthermore, not only the ionization potential but also geometry and IR frequencies of problematic double radicals are estimated correctly, and the results are comparable to the CCSD(T) method, obviously at lesser computational cost. The EOMIP-CCSD(2)* method works even for the core ionization and satellite IP, where the earlier EOMIP-CCSD(2) approximation dramatically fails.

1 aDutta, Achintya, Kumar1 aVaval, Nayana1 aPal, Sourav uhttps://library.ncl.res.in/content/eomip-ccsd2-efficient-method-calculation-ionization-potentials-102036nas a2200193 4500008004100000022001400041245016500055210006900220260007900289300001100368490000700379520123500386100001801621700002001639700002201659700001801681700001601699856012701715 2015 eng d a2469-992600aImplementation of the Z-vector method in the relativistic-coupled-cluster framework to calculate first-order energy derivatives: Application to the SrF molecule0 aImplementation of the Zvector method in the relativisticcoupledc aONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USAbAMER PHYSICAL SOCcMAR a0305030 v913 a

The molecular dipole moment and magnetic hyperfine-structure constant demand an accurate wave function far from the nucleus and in the near nuclear region, respectively. We, therefore, employ the so-called Z-vector method in the domain of relativistic-coupled-cluster theory to calculate the first-order property of molecular systems in their open-shell ground-state configuration. The implemented method is applied to calculate the molecular dipole moment and parallel component of the magnetic hyperfine-structure constant of the SrF molecule. The results of our calculation are compared with the experimental and other available theoretically calculated values. We are successful in achieving good accordance with the experimental results. The result of our calculation of the molecular dipole moment is in the accuracy of similar to 0.5%, which is clearly an improvement over the previous calculation based on the expectation value method in the four-component coupled-cluster framework [V. S. Prasannaa et al., Phys. Rev. A 90, 052507 (2014)]. Thus, it can be inferred that the Z-vector method can provide an accurate wave function in both the near and far nuclear region, which is evident from our calculated results.

1 aSasmal, Sudip1 aPathak, Himadri1 aNayak, Malaya, K.1 aVaval, Nayana1 aPal, Sourav uhttps://library.ncl.res.in/content/implementation-z-vector-method-relativistic-coupled-cluster-framework-calculate-first-100583nas a2200145 4500008004100000245011100041210006900152260000800221300002300229490000800252100001700260700001600277700001800293856012600311 2015 eng d00aLifetime of inner-shell hole states of Ar (2p) and Kr (3d) using equation-of-motion coupled cluster method0 aLifetime of innershell hole states of Ar 2p and Kr 3d using equa cJUL aArticle No. 0243050 v1431 aGhosh, Aryya1 aPal, Sourav1 aVaval, Nayana uhttps://library.ncl.res.in/content/lifetime-inner-shell-hole-states-ar-2p-and-kr-3d-using-equation-motion-coupled-cluster01795nas a2200169 4500008004100000022001400041245015800055210006900213260008700282300002300369490000800392520103500400100002701435700001801462700001601480856012901496 2015 eng d a0021-960600aNew scheme for perturbative triples correction to (0,1) sector of Fock space multi-reference coupled cluster method: Theory, implementation, and examples0 aNew scheme for perturbative triples correction to 01 sector of F a1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USAbAMER INST PHYSICScJAN aArticle No. 0441130 v1423 a

We propose a new elegant strategy to implement third order triples correction in the light of many-body perturbation theory to the Fock space multi-reference coupled cluster method for the ionization problem. The computational scaling as well as the storage requirement is of key concerns in any many-body calculations. Our proposed approach scales as N-6 does not require the storage of triples amplitudes and gives superior agreement over all the previous attempts made. This approach is capable of calculating multiple roots in a single calculation in contrast to the inclusion of perturbative triples in the equation of motion variant of the coupled cluster theory, where each root needs to be computed in a state-specific way and requires both the left and right state vectors together. The performance of the newly implemented scheme is tested by applying to methylene, boron nitride (B2N) anion, nitrogen, water, carbon monoxide, acetylene, formaldehyde, and thymine monomer, a DNA base. (C) 2015 AIP Publishing LLC.

1 aDutta, Achintya, Kumar1 aVaval, Nayana1 aPal, Sourav uhttps://library.ncl.res.in/content/new-scheme-perturbative-triples-correction-01-sector-fock-space-multi-reference-coupled-101942nas a2200169 4500008004100000022001400041245006400055210006300119260011000182300001600292490000600308520131200314100002201626700001701648700001601665856009101681 2015 eng d a2040-336400aOxidative addition of the C-I bond on aluminum nanoclusters0 aOxidative addition of the CI bond on aluminum nanoclusters aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcJUN a12109-121250 v73 a

Energetics and the in-depth reaction mechanism of the oxidative addition step of the cross-coupling reaction are studied in the framework of density functional theory (DFT) on aluminum nanoclusters. Aluminum metal in its bulk state is totally inactive towards carbon-halogen bond dissociation but selected Al nanoclusters (size ranging from 3 to 20 atoms) have shown a significantly lower activation barrier towards the oxidative addition reaction. The calculated energy barriers are lower than the gold clusters and within a comparable range with the conventional and most versatile Pd catalyst. Further investigations reveal that the activation energies and other reaction parameters are highly sensitive to the geometrical shapes and electronic structures of the clusters rather than their size, imposing the fact that comprehensive studies on aluminum clusters can be beneficial for nanoscience and nanotechnology. To understand the possible reaction mechanism in detail, the reaction pathway is investigated with the ab initio Born Oppenheimer Molecular Dynamics (BOMD) simulation and the Natural Bond Orbital (NBO) analysis. In short, our theoretical study highlights the thermodynamic and kinetic details of C-I bond dissociation on aluminum clusters for future endeavors in cluster chemistry.

1 aSengupta, Turbasu1 aDas, Susanta1 aPal, Sourav uhttps://library.ncl.res.in/content/oxidative-addition-c-i-bond-aluminum-nanoclusters-001372nas a2200241 4500008004100000020002200041022001400063245012000077210006900197260012300266300001200389490000900401520045100410653001800861653002000879653001200899100002600911700001800937700001600955700001400971700001600985856012901001 2015 eng d a978-0-7354-1282-8 a0094-243X00aPartial triples excitation to the fock space multi-reference singles and doubles: dipole moment of doublet radicals0 aPartial triples excitation to the fock space multireference sing a2 Huntington Quadrangle, STE 1NO1, Melville, NY 11747-4501 USAbEuropean Soc Computat Methods Sci, Engn & TechnolcFEB a223-2260 v16423 a

We present the partial triples effect on the dipole moment of doublet radicals in Lagrangian formulation of Fockspace multi-reference coupled cluster response method(A FSMRCC). This specific scheme uses non-iterative triples, in addition to singles and doubles excitations(A FSMRCCSD(T*)), which accounts for the effects appearing at least at the third order in dipole moment. This method is applied to the ground states of small radicals.

10aDipole moment10aMulti-reference10aTriples1 aRavichandran, Lalitha1 aVaval, Nayana1 aPal, Sourav1 aSimos, TE1 aMaroulis, G uhttps://library.ncl.res.in/content/partial-triples-excitation-fock-space-multi-reference-singles-and-doubles-dipole-moment-002044nas a2200229 4500008004100000022001400041245016300055210006900218260009200287300001400379490000800393520108200401653003301483653001501516653002301531653003901554100002701593700002701620700002001647700001601667856013101683 2015 eng d a0026-897600aPerturbative order analysis of the similarity transformed hamiltonian in fock-space coupled cluster theory: difference energy and electric response properties0 aPerturbative order analysis of the similarity transformed hamilt a4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLANDbTAYLOR & FRANCIS LTDcJUL a2046-20600 v1133 a

A perturbative analysis of the ground-state similarity transformed Hamiltonian and its effect on the various Fock-space coupled cluster (FSCC) sectors is presented through calculation of ionisation potential, electron affinity, excitation energies and response properties. Various truncation schemes of the effective Hamiltonian are presented with explicit form of the defining equations. Based on such a truncation, the approximate methods are labelled as FSCC(n), where n represents the correlation energy of the ionised, electron attached or excited states corrected at least up to nth order within coupled cluster singles and doubles scheme (CCSD). A lower scaling CC2 type of approach (abbreviated as FS-CC2) is compared against the group of FSCC(n) methods for energies. Electric response properties have been compared and contrasted for the two lower scaling methods: FSCC(2) and FS-CC2. The various truncated methods are tested for a number of small molecules. The results obtained from a range of truncated methods are compared against full FSCCSD calculations.

10aelectric response properties10aFock space10aperturbative order10asimilarity transformed Hamiltonian1 aBhattacharya, Debarati1 aDutta, Achintya, Kumar1 aGupta, Jitendra1 aPal, Sourav uhttps://library.ncl.res.in/content/perturbative-order-analysis-similarity-transformed-hamiltonian-fock-space-coupled-cluster-002235nas a2200157 4500008004100000022001400041245008300055210006900138260007100207300001400278490000800292520162700300100001701927700001601944856011701960 2015 eng d a1089-563900aReactivity and catalytic activity of hydrogen atom chemisorbed silver clusters0 aReactivity and catalytic activity of hydrogen atom chemisorbed s a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcJUN a6162-61700 v1193 a

Metal clusters of silver have attracted recent interest of researchers as a result of their potential in different,catalytic applications and low Cost. However, due to the completely filled d orbital and very high first ionization potential of the silver atom, the silver-based catalysts interact very weakly with the reacting molecules. In the current work, density functional theory calculations were carried out to investigate the effect of hydrogen atom chemisorption. On the reactivity and catalytic properties of inert silver clusters Our results affirm that the hydrogen atom chemisorption leads to enhancement the binding energy of the adsorbed O-2 molecule on the inert silver clusters. The increase in the binding energy is also characterized by the decrease in the Ag-O and increase in the O-O bond lengths in the case of the AgnH Silver clusters. Pertinent to the increase in the O-O bond length, a. significant red shift in the O-O Stretching frequency is. also noted in the case,of the AgnH silver clusters. Moreover, the hydrogen atom chemisorbed silver clusters show low reaction barriers and heat Of formation of the final products for the,environmentally important CO oxidation reaction as compared to the parent catalytically inactive clusters The obtained results were compared with those of the corresponding gold and hydrogen atom chemisorbed gold clusters obtained at the same level of theory. It is expected the current computational study will provide key insights for future advances in the design of efficient nanosilver-based catalysts through the adsorption of a small atom or a ligand.

1 aManzoor, Dar1 aPal, Sourav uhttps://library.ncl.res.in/content/reactivity-and-catalytic-activity-hydrogen-atom-chemisorbed-silver-clusters-001855nas a2200241 4500008004100000022001400041245016200055210006900217260008100286300001100367490000700378520090300385653002701288653003301315653003001348100002001378700001801398700002201416700001601438700001801454700001601472856012501488 2015 eng d a0953-407500aRelativistic equation-of-motion coupled-cluster investigation of the trends of single and double ionization potentials in the He and Be isoelectronic systems0 aRelativistic equationofmotion coupledcluster investigation of th aTEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLANDbIOP PUBLISHING LTDcJUN a1150090 v483 a

We employ a four-component spinor relativistic equation-of-motion coupled-cluster (EOMCC) method within the single-and double-excitation approximation to calculate the single ionization potentials (IPs) and double ionization potentials (DIPs) of the He and Be isoelectronic sequences up to Ne. The obtained results are compared with the available results from the National Institute of Standards and Technology (NIST) database to test the performance of the EOMCC method. We also present intermediate results at different levels of approximations in the EOMCC framework to gain insight of the effect of electron correlation. Furthermore, we investigate the dependence of the IPs and DIPs of these ions on the ionic charge and observe that these follow parabolic trends. Similarities between the trends of IPs and DIPs in both the classes of considered systems are categorically demonstrated.

10acoupled-cluster method10adouble ionization potentials10aequation-of-motion theory1 aPathak, Himadri1 aSahoo, B., K.1 aSengupta, Turbasu1 aDas, B., P.1 aVaval, Nayana1 aPal, Sourav uhttps://library.ncl.res.in/content/relativistic-equation-motion-coupled-cluster-investigation-trends-single-and-double-100625nas a2200169 4500008004100000245009100041210006900132260000800201300002300209490000700232100001800239700002000257700002200277700001800299700001600317856012200333 2015 eng d00aRelativistic extended coupled cluster method for magnetic hyperfine structure constant0 aRelativistic extended coupled cluster method for magnetic hyperf cFEB aArticle No. 0225120 v911 aSasmal, Sudip1 aPathak, Himadri1 aNayak, Malaya, K.1 aVaval, Nayana1 aPal, Sourav uhttps://library.ncl.res.in/content/relativistic-extended-coupled-cluster-method-magnetic-hyperfine-structure-constant01602nas a2200241 4500008004100000020002200041022001400063245007700077210006900154260012300223300001200346490000900358520074700367653001001114653002301124653002301147100001901170700001601189700001801205700001401223700001601237856010701253 2015 eng d a978-0-7354-1282-8 a0094-243X00aStudy of molecular vibration by coupled cluster method: bosonic approach0 aStudy of molecular vibration by coupled cluster method bosonic a a2 Huntington Quadrangle, STE 1NO1, Melville, NY 11747-4501 USAbEuropean Soc Computat Methods Sci, Engn & TechnolcFEB a227-2300 v16423 a

The vibrational coupled cluster method in bosonic representation is formulated to describe the molecular anharmonic vibrational spectra. The vibrational coupled cluster formalism is based on Watson Hamiltonian in normal coordinates. The vibrational excited states are described using coupled cluster linear response theory (CCLRT). The quality of the coupled cluster wave function is analyzed. Specifically, the mean displacement values of the normal coordinates and expectation values of the square of the normal coordinates of different vibrational states are calculated. A good agreement between the converged full CI results and coupled cluster results is found for the lower lying vibrational states.

10aCCLRT10aExpectation values10aWatson Hamiltonian1 aBanik, Subrata1 aPal, Sourav1 aPrasad, Durga1 aSimos, TE1 aMaroulis, G uhttps://library.ncl.res.in/content/study-molecular-vibration-coupled-cluster-method-bosonic-approach-000782nas a2200193 4500008004100000022001400041245012500055210006900180260007300249300001200322490000800334100002200342700001800364700001600382700002800398700002500426700002500451856011200476 2015 eng d a0009-261400aSystematic comparison of DFT and CCSD dipole moments, polarizabilities and hyperpolarizabilities (vol 635, pg 168, 2015)0 aSystematic comparison of DFT and CCSD dipole moments polarizabil aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcSEP a228-2290 v6361 aKarne, Anagha, S.1 aVaval, Nayana1 aPal, Sourav1 aVasquez-Perez, Jose, M.1 aKoester, Andreas, M.1 aCalaminici, Patrizia uhttps://library.ncl.res.in/content/systematic-comparison-dft-and-ccsd-dipole-moments-polarizabilities-and-101619nas a2200205 4500008004100000022001400041245010100055210006900156260007300225300001200298490000800310520084900318100002201167700001801189700001601207700002801223700002501251700002501276856011201301 2015 eng d a0009-261400aSystematic comparison of DFT and CCSD dipole moments, polarizabilities and hyperpolarizabilities0 aSystematic comparison of DFT and CCSD dipole moments polarizabil aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcAUG a168-1730 v6353 a

A comparative study of dipole moments, polarizabilities and hyperpolarizabilities of 16 different molecules is performed employing two completely different theoretical approaches namely, density functional theory (DFT) and coupled cluster singles and doubles (CCSD). Both methods include electron correlation. The CCSD method is more accurate but highly expensive. DFT with auxiliary density allows non-iterative solutions which is computational advantage and useful for large molecules. Dipole moments and polarizability calculations from DFT are in very good agreement with CCSD calculations. However, negative hyperpolarizability values from DFT differ significantly from their CCSD counterparts, whereas positive hyperpolarizabilities show reasonable agreement between these methodologies. (C) 2015 Elsevier B.V. All rights reserved.

1 aKarne, Anagha, S.1 aVaval, Nayana1 aPal, Sourav1 aVasquez-Perez, Jose, M.1 aKoester, Andreas, M.1 aCalaminici, Patrizia uhttps://library.ncl.res.in/content/systematic-comparison-dft-and-ccsd-dipole-moments-polarizabilities-and-201296nas a2200181 4500008004100000245013600041210006900177260000800246300001400254490000800268520061000276100001800886700002200904700002200926700001800948700001600966856013200982 2016 eng d00aCalculation of hyperfine structure constants of small molecules using Z-vector method in the relativistic coupled-cluster framework0 aCalculation of hyperfine structure constants of small molecules  cOCT a1671-16750 v1283 aThe Z-vector method in the relativistic coupled-cluster framework is employed to calculate the parallel and perpendicular components of the magnetic hyperfine structure constant of a few small alkaline earth hydrides (BeH, MgH, and CaH) and fluorides (MgF and CaF). We have compared our Z-vector results with the values calculated by the extended coupled-cluster (ECC) method reported in Phys. Rev. A 91 022512 (2015). All these results are compared with the available experimental values. The Z-vector results are found to be in better agreement with the experimental values than those of the ECC values.1 aSasmal, Sudip1 aTalukdar, Kaushik1 aNayak, Malaya, K.1 aVaval, Nayana1 aPal, Sourav uhttps://library.ncl.res.in/content/calculation-hyperfine-structure-constants-small-molecules-using-z-vector-method-relativistic01930nas a2200157 4500008004100000245016500041210006900206260000800275300001600283490000800299520127400307100001701581700002601598700001601624856013201640 2016 eng d00aContriving a catalytically active structure from an inert conformation: a density functionalinvestigation of Al, Hf, and Ge doping of Au-20 tetrahedral clusters0 aContriving a catalytically active structure from an inert confor cSEP a19636-196410 v1203 a

The transformation of an inert structure into a catalytically active conformation has immense potential from a structural engineering point of view. In the present work, we explored methods of achieving such a transformation through a density-functional-based study. Au-20 is known be one of the most stable and catalytically inert gold clusters, with a well-known tetrahedral structure. We demonstrate the transformation of the inert Au-20 conformation into a highly active catalytic cluster through selective doping with Hf and Ge atoms. Depending on the dopant, the inert tetrahedral Au-20 cluster evolves into either an endohedral or a hollow-cage-like conformation. The structural changes are manifested in the catalytic properties as well, with the result that the transformed doped cages exhibit extremely low activation barriers for the environmentally important CO oxidation reaction as compared to reported inert Au-20 cluster. The activation barriers for CO oxidation are particularly low (<0.12 eV) when germanium is directly involved in the CO oxidation. Thus, the current work highlights the importance of engineering structural properties of metal nanoclusters with the help of heteroatom dopants for future applications in efficient catalysis.

1 aManzoor, Dar1 aKrishnamurty, Sailaja1 aPal, Sourav uhttps://library.ncl.res.in/content/contriving-catalytically-active-structure-inert-conformation-density-functionalinvestigation01519nas a2200181 4500008004100000022001400041245007600055210006900131260007100200300001400271490000800285520085200293100001701145700002201162700002701184700001601211856011001227 2016 eng d a1089-563900aElectron detachment and subsequent structural changes of water clusters0 aElectron detachment and subsequent structural changes of water c a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcFEB a1065-10730 v1203 a

A cost-effective equation of motion coupled cluster method, EOMIP-CCSD(2), is used to investigate vertical and adiabatic ionization potential as well as ionization-induced structural changes of water clusters and compared with CCSD(T), CASPT2, and MP2 methods. The moderate N-5 scaling and low storage requirement yields EOMIP-CCSD (2) calculation feasible even for reasonably large molecules and clusters with accuracy comparable to CCSD(T) method at much cheaper computational cost. Our calculations shed light on the authenticity of EOMIP-CCSD(2) results and establish a reliable method to study of ionization energy of molecular clusters. We have further investigated the performance of several classes of DFT functionals for ionization energies of water clusters to benchmark the results and to get a reliable functionals for the same.

1 aDas, Susanta1 aSengupta, Turbasu1 aDutta, Achintya, Kumar1 aPal, Sourav uhttps://library.ncl.res.in/content/electron-detachment-and-subsequent-structural-changes-water-clusters-002379nas a2200169 4500008004100000022001400041245009500055210006900150260011000219300001400329490000700343520167300350100001702023700002602040700001602066856012702082 2016 eng d a1463-907600aEndohedrally doped gold nanocages: efficient catalysts for O-2 activation and CO oxidation0 aEndohedrally doped gold nanocages efficient catalysts for O2 act aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcMAR a7068-70740 v183 a

Gold nanocages are the most attractive catalytic materials as all the atoms in the cage type clusters reside on the surface, making them available for chemisorption by reacting molecules. Due to a hollow space at the center, their chemical and catalytic properties can be tuned effectively and easily by endohedral doping. While a significant experimental and theoretical understanding is currently available on the structural and electronic properties of doped gold cages, very little information is available on their reactivity and catalytic behavior. In the present work, with the help of density functional theory calculations we demonstrate that endohedral doping leads to a notable increase in the binding energy of molecular oxygen on the gold nanocages. The enhancement in the O-2 binding energy on the doped gold cages is also confirmed by a significant decrease in the Au-O and an increase in the O-O bond lengths, corroborated by a red shift (similar to 250 cm(-1)) in the O-O stretching frequency as compared to the pristine cage. Furthermore, interestingly, the doped gold cages show very low activation barriers for the environmentally important CO oxidation reaction as compared to the pristine gold cage. Importantly, the decrease in the barrier height is comparatively greater for the rate limiting step of O-O-C-O intermediate formation and as a result the CO oxidation is expected to be more facile on the doped gold cages. Thus, the current study highlights the role of heteroatom doping in imparting new chemical and catalytic properties to gold cages and is expected to spur further research in the design of efficient gold nanocatalysts.

1 aManzoor, Dar1 aKrishnamurty, Sailaja1 aPal, Sourav uhttps://library.ncl.res.in/content/endohedrally-doped-gold-nanocages-efficient-catalysts-o-2-activation-and-co-oxidation-001326nas a2200169 4500008004100000022001400041245007900055210006900134260007300203300001200276490000800288520069600296100001700992700002301009700001601032856010801048 2016 eng d a0009-261400aHydrogen adsorption in ZIF-7: A DFT and ab-initio molecular dynamics study0 aHydrogen adsorption in ZIF7 A DFT and abinitio molecular dynamic aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcMAY a178-1820 v6513 a

Primary H-2 adsorption sites in a zeolitic imidazolate framework, ZIF-7, are identified using ab-initio density functional theory (DFT) based molecular dynamics annealing simulations. The simulations suggest several low energy adsorption sites. The effect of light transition metal decoration on hydrogen storage properties was studied. Our ab-intio DFT calculations illustrate that decorating the ZIF with Sc increases both the number of H-2 molecules, as well as the H-2 binding energy. The binding energy (similar to 25 kJ/mol per H-2) at 8H(2) loading in the pore, suggests that Sc-ZIFs can be potential candidates for hydrogen storage. (C) 2016 Elsevier B.V. All rights reserved.

1 aDixit, Mudit1 aMajor, Dan, Thomas1 aPal, Sourav uhttps://library.ncl.res.in/content/hydrogen-adsorption-zif-7-dft-and-ab-initio-molecular-dynamics-study01680nas a2200169 4500008004100000245007800041210006900119260000800188300001600196490000700212520111300219100002001332700001801352700002001370700001601390856010401406 2016 eng d00aInfluence of carbon and phosphorus doping on electronic properties of ZnO0 aInfluence of carbon and phosphorus doping on electronic properti cDEC a12318-123220 v273 aZnO is one of the most promising candidate for photoelectrochemical splitting of water for hydrogen production. To increase the efficiency of ZnO based photoelectrochemical cell, its band-gap and band edges should be tailored to match visible light spectra and water redox potential respectively. In this paper, First-principles density functional theory calculations have been performed to evaluate the effect of non-metal dopants on electronic properties of ZnO. The model structures of X-doped ZnO were constructed using 32-atom 2 x 2 x 2 supercell of wurtzite ZnO with one O atom replaced with X (carbon C, phosphorus P). With respect to the electronic band structure, C (2p), P (3p) states are located above the valence band maximum of ZnO and mixing of these states is feeble to produce significant band gap narrowing. Doping of these non-metals dopants helps in the creation of isolated states which enhances visible light absorption of ZnO. Our theoretical calculations are consistent with the experimental results of C (P) doped ZnO and fully explains its visible light activity on non-metal doping.1 aSharma, Vidhika1 aPrasad, Mohit1 aJadkar, Sandesh1 aPal, Sourav uhttps://library.ncl.res.in/content/influence-carbon-and-phosphorus-doping-electronic-properties-zno01360nas a2200157 4500008004100000245008600041210006900127260000800196300001600204490000700220520080100227100001801028700001601046700002601062856011401088 2016 eng d00aN-2 activation on Al metal clusters: catalyzing role of BN-doped graphene support0 aN2 activation on Al metal clusters catalyzing role of BNdoped gr cOCT a27721-277270 v183 aThe successful sustenance of life demands an ambient abiotic process for N-2 activation and dissociation. The Bosch-Haber process remains the only abiotic and synthetic means for N-2 activation and its fixation. Metal nanoclusters have been recently reported for activating molecular nitrogen. Interestingly, the metal clusters explored so far for N-2 activation are free clusters and, hence, are practically not applicable by experimental chemists. Using density functional theory (DFT) based methodology, we propose a potential catalytic system for di-nitrogen activation, viz. supported Al clusters. Al clusters supported on BN doped graphene sheets are seen to activate N-2 molecule with a red shift in the N-N stretching frequency up to 874 cm(-1) with activation barriers as low as 1.14 eV.1 aKumar, Deepak1 aPal, Sourav1 aKrishnamurty, Sailaja uhttps://library.ncl.res.in/content/n-2-activation-al-metal-clusters-catalyzing-role-bn-doped-graphene-support01904nas a2200157 4500008004100000022001400041245008800055210006900143260011000212300001600322490000700338520124700345100002201592700001601614856011601630 2016 eng d a1463-907600aRadical attached aluminum nanoclusters: an alternative way of cluster stabilization0 aRadical attached aluminum nanoclusters an alternative way of clu aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcAUG a21746-217590 v183 a

The stability and electronic structure of radical attached aluminum nanoclusters are investigated using density functional theory (DFT). A detailed investigation shows good correlation between the thermodynamic stability of radical attached clusters and the stability of the attached radical anions. All other calculated parameters like HOMO-LUMO gap and charge transfer are also found to be consistent with the observed thermodynamic stabilities of the complexes. Investigation of the electronic structure of radical attached complexes further shows the presence of jellium structures within the core similar to the ligated clusters. Comparison with available experimental and theoretical data also proves the validity of superatomic complex theory for the radical attached clusters as well. Based on the evaluated thermodynamic parameters, selected radical attached clusters are observed to be more thermodynamically stable in comparison with experimentally synthesized ligated clusters. Stabilization of small metal clusters is one of the greatest challenges in current cluster science and the present investigation confirms the fact that radical attached clusters can provide a viable alternative to ligated clusters in the future.

1 aSengupta, Turbasu1 aPal, Sourav uhttps://library.ncl.res.in/content/radical-attached-aluminum-nanoclusters-alternative-way-cluster-stabilization01797nas a2200193 4500008004100000022001400041245011700055210006900172260007900241300001100320490000700331520104800338100001801386700002001404700002201424700001801446700001601464856012301480 2016 eng d a2469-992600aRelativistic coupled-cluster study of RaF as a candidate for the parity- and time-reversal-violating interaction0 aRelativistic coupledcluster study of RaF as a candidate for the  aONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USAbAMER PHYSICAL SOCcJUN a0625060 v933 a

We have employed both the Z-vector method and the expectation-value approach in the relativistic coupled-cluster framework to calculate the scalar-pseudoscalar (S-PS) P, T-odd interaction constant W-s and the effective electric field E-eff experienced by the unpaired electron in the ground electronic state of RaF. Further, the magnetic hyperfine structure constants of Ra-223 in RaF and Ra-223(+) are also calculated and compared with the experimental values wherever available to judge the extent of the accuracy obtained with the employed methods. The outcome of our study reveals that the Z-vector method is superior to the expectation-value approach in terms of accuracy obtained for the calculation of ground-state property. The Z-vector calculation shows that RaF has a high Eeff (52.5 GV/cm) and W-s (141.2 kHz), which makes it a potential candidate for the electric dipole moment of the electron (eEDM) experiment. An estimation of uncertainty associated with our final results is made, and it is found that it lies below 10%.

1 aSasmal, Sudip1 aPathak, Himadri1 aNayak, Malaya, K.1 aVaval, Nayana1 aPal, Sourav uhttps://library.ncl.res.in/content/relativistic-coupled-cluster-study-raf-candidate-parity-and-time-reversal-violating01514nas a2200181 4500008004100000245009500041210006900136260000800205300001100213490000900224520088600233100002001119700001801139700002201157700001801179700001601197856011901213 2016 eng d00aRelativistic equation-of-motion coupled-cluster method for the electron attachment problem0 aRelativistic equationofmotion coupledcluster method for the elec cJAN a94-1000 v10763 a

The article considers the successful implementation of relativistic equation-of-motion coupled cluster method for the electron attachment problem (EA-EOMCC) at the level of single- and double- excitation approximation. The implemented relativistic EA-EOMCC method is employed to calculate ionization potential values of alkali metal atoms (Li, Na, K, Rb, Cs, Fr) and the vertical electron affinity values of LiX (X = H, F, Cl, Br), NaY (Y = H, F, Cl) starting from their closed-shell configuration. Both four component and exact two-component calculations are done for all the opted systems. Further, we have shown the effect of spin-orbit interaction considering the atomic systems. The results of our atomic calculations are compared with the values from the NIST database and the results are found to be very accurate (<1%). (C) 2015 Elsevier B.V. All rights reserved.

1 aPathak, Himadri1 aSasmal, Sudip1 aNayak, Malaya, K.1 aVaval, Nayana1 aPal, Sourav uhttps://library.ncl.res.in/content/relativistic-equation-motion-coupled-cluster-method-electron-attachment-problem01872nas a2200181 4500008004100000245010100041210006900142260000800211300002300219490000800242520121800250100001801468700002001486700002201506700001801528700001601546856012801562 2016 eng d00aSearch for parity and time reversal violating effects in HgH: relativistic coupled-cluster study0 aSearch for parity and time reversal violating effects in HgH rel cMAR aArticle No. 1243070 v1443 a

The high effective electric field (E-eff) experienced by the unpaired electron in an atom or a molecule is one of the key ingredients in the success of electron electric dipole moment (eEDM) experiment and its precise calculation requires a very accurate theory. We, therefore, employed the Z-vector method in the relativistic coupled-cluster framework and found that HgH has a very large E-eff value (123.2 GV/cm) which makes it a potential candidate for the next generation eEDM experiment. Our study also reveals that it has a large scalar-pseudoscalar (S-PS) P, T-violating interaction constant, W-s = 284.2 kHz. To judge the accuracy of the obtained results, we have calculated parallel and perpendicular magnetic hyperfine structure (HFS) constants and compared with the available experimental values. The results of our calculation are found to be in nice agreement with the experimental values. Therefore, by looking at the HFS results, we can say that both E-eff and W-s values are also very accurate. Further, We have derived the relationship between these quantities and the ratio which will help to get model independent value of eEDM and S-PS interaction constant. (C) 2016 AIP Publishing LLC.

1 aSasmal, Sudip1 aPathak, Himadri1 aNayak, Malaya, K.1 aVaval, Nayana1 aPal, Sourav uhttps://library.ncl.res.in/content/search-parity-and-time-reversal-violating-effects-hgh-relativistic-coupled-cluster-study02241nas a2200193 4500008004100000022001400041245018100055210006900236260000900305300001200314490000600326520148200332100002301814700001801837700002401855700001601879700002401895856012801919 2016 eng d a2196-735000aStrategic Preparation of Efficient and Durable NiCo Alloy Supported N-Doped Porous Graphene as an Oxygen Evolution Electrocatalyst: A Theoretical and Experimental Investigation0 aStrategic Preparation of Efficient and Durable NiCo Alloy Suppor cOCT  a16005320 v33 a

Development of an efficient and durable water splitting electrocatalyst holds a great commitment for the future energy devices. The real application of oxygen evolution reaction (OER) catalysts mainly suffers from sluggish kinetics and high overpotential except for the Ir and Ru-based systems. However, the high cost and vulnerability of the Ir and Ru metals are the main hostiles to use them for marketization. Herein, a high-performance OER electrocatalyst consisting of NiCo alloy nanoparticles supported on high surface area N-doped porous graphene (NiCo/pNGr(75: 25)) is reported. The importance of the doped-N for achieving the uniform dispersion-cum-effective interaction of the size controlled NiCo alloy nanoparticles has been explicitly investigated by transmission electron microscopy, X-ray diffraction, X-ray photo electron spectroscopy, Raman, density functional theory (DFT) calculations, etc. The electrochemical analysis of NiCo/pNGr(75: 25) shows an overpotential of approximate to 260 mV at 10 mA cm(-2) with a smaller Tafel slope of approximate to 87 mV dec(-1) and long catalytic durability. DFT calculations are done to check the interaction between the NiCo alloy nanoparticles and the defective sites of pNGr and also with the doped-N, which could be attained for maintaining long catalytic durability. Furthermore, NiCo/pNGr(75: 25) is used as an OER catalyst to fabricate an electrolyzer, which works at very low potential of 1.5 V in 1 M KOH.

1 aSingh, Santosh, K.1 aKumar, Deepak1 aDhavale, Vishal, M.1 aPal, Sourav1 aKurungot, Sreekumar uhttps://library.ncl.res.in/content/strategic-preparation-efficient-and-durable-nico-alloy-supported-n-doped-porous-graphene01784nas a2200169 4500008004100000022001400041245006500055210006400120260007100184300001600255490000800271520118700279100002201466700001701488700001601505856009301521 2016 eng d a1932-744700aTransition metal doped aluminum clusters: an account of spin0 aTransition metal doped aluminum clusters an account of spin a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcMAY a10027-100400 v1203 a

The influence of spin on the properties of small sized transition metal doped aluminum clusters are investigated in the framework of density functional theory (DFT). Detailed analysis on minimum spin doped aluminum clusters has shown prominent indication of odd even oscillation in various calculated properties, supporting the presence of jellium shell structures within them. However, optimized high spin ground state counterparts, on the other hand, show rather smooth trends consistent with the properties of bulk materials. Resemblance to the bulk transition metals is further reflected in the gradual declining trends of heat of adsorption of CO2 molecule on cluster surface by sequentially changing the dopant atom from scandium to zinc. All the observations are also compared and found to be consistent with the earlier theoretical and experimental findings as obtained in the current literature. The similarities in the properties between atomic clusters and the bulk material is of utter importance and indeed precious considering the promising influence of the acquired information in understanding the process of evolution of nanoparticles from constituent atoms.

1 aSengupta, Turbasu1 aDas, Susanta1 aPal, Sourav uhttps://library.ncl.res.in/content/transition-metal-doped-aluminum-clusters-account-spin01439nas a2200157 4500008004100000245009000041210006900131260000800200300001200208490001000220520088100230100001701111700001801128700001601146856011901162 2017 eng d00aAuger decay rates of core hole states using equation of motion coupled cluster method0 aAuger decay rates of core hole states using equation of motion c cJAN a160-1640 v482 3 aThe recent development of Linac coherent light source high intense X-ray laser makes it possible to create double core ionization in the molecule. The generation of double core hole state and its decay is identified by Auger spectroscopy. The decay of this double core hole (DCH) states can be used as a powerful spectroscopic tool in chemical analysis. In the present work, we have implemented a promising approach, known as CAP-EOMCC method, which is a combination of complex absorbing potential (CAP) and equation -of-motion coupled cluster (EOMCC) approach to calculate the lifetime of single and double core hole states. We have applied this method to calculate the lifetime of the single core hole (K-LL) and double core hole (KK-KLL) states of CH4, NH3 and HF molecules. The predicted lifetime is found to be extremely short. (C) 2016 Elsevier B.V. All rights reserved.1 aGhosh, Aryya1 aVaval, Nayana1 aPal, Sourav uhttps://library.ncl.res.in/content/auger-decay-rates-core-hole-states-using-equation-motion-coupled-cluster-method01246nas a2200157 4500008004100000245009900041210006900140260000800209300001600217490000800233520065900241100001800900700002600918700001600944856012800960 2017 eng d00aDissociative adsorption of molecular hydrogen on BN-doped graphene-supported aluminum clusters0 aDissociative adsorption of molecular hydrogen on BNdoped graphen cNOV a26493-264980 v1213 aThe present work demonstrates dissociative adsorption of molecular hydrogen on supported and unsupported aluminum Wclusters (Al-n, n = 4-8, 13) using density functional theory based calculations. The studies reveal that the presence of a BN-doped graphene surface support reduces the dissociative adsorption barrier of the bond in molecular hydrogen on even atom clusters. In particular, supported Al-6 demonstrates a barrier-less dissociative adsorption toward the H-2 molecule. These results demonstrate the excellent potential of supported Al nanoparticles for hydrogen storage and also the potential of doped graphene systems are catalyzing supports.1 aKumar, Deepak1 aKrishnamurty, Sailaja1 aPal, Sourav uhttps://library.ncl.res.in/content/dissociative-adsorption-molecular-hydrogen-bn-doped-graphene-supported-aluminum-clusters01880nas a2200157 4500008004100000245011500041210006900156260000800225300001600233490000800249520128700257100002201544700002001566700001601586856012001602 2017 eng d00aEffect of ligand attachment on the C-I bond dissociation process on aluminum nanoclusters: a DFT investigation0 aEffect of ligand attachment on the CI bond dissociation process  cAUG a17354-173640 v1213 aThe influence of the ligand attachment on the activation process of carbon halogen bond on small sized aluminum nanoclusters are investigated using density functional theory. Attaching suitable ligand to metal clusters is among the widely popular techniques often used by experimentalists in order to stabilize metastable clusters. In depth theoretical investigations have shown that based on the jellium configuration of the cluster, attaching an electron withdrawing ligand can either make a cluster more reactive toward the C-I dissociation or may convert the cluster relatively inert. The alteration of the activation barriers and other associated parameters due to ligand attachment are included in this paper along with additional calculations and explanations. The study also shows that even the reaction parameters of specific magic clusters can be significantly altered via ligand attachment. The activation process of small molecules on metal clusters are of crucial importance for the development of material science and cluster chemistry. The present investigation will therefore be useful for better understanding of the properties of the ligated clusters as well as may also aid the experimentalists toward controlling the reactivity of a specific cluster as required.1 aSengupta, Turbasu1 aSamanta, Bipasa1 aPal, Sourav uhttps://library.ncl.res.in/content/effect-ligand-attachment-c-i-bond-dissociation-process-aluminum-nanoclusters-dft01695nas a2200157 4500008004100000245009700041210006900138260000800207300001400215490000800229520112100237100002201358700002301380700001601403856011801419 2017 eng d00aMechanistic investigation of the carbon-iodine bond activation on the niobium-carbon cluster0 aMechanistic investigation of the carboniodine bond activation on cSEP a5335-53470 v2 3 a

The activation process of carbon-iodine (C-I) bond on neutral and cationic niobium metcars (Nb8C12) is investigated using density functional theory and related computational techniques. Metallocarbohedrenes or metcars are a class of stable metal-carbide clusters of specific stoichiometry and of great interest to cluster chemists since their first discovery. The detailed reaction mechanism along with the overall energy profile of the C-I dissociation reaction on niobium metcar and its cations is presented in this paper. The tunneling-corrected rate constants and their related reaction parameters such as the pre-exponential factor are also included alongside. The major differences between the reaction mechanism of the neutral and cationic metcars are also highlighted as well. Despite the available experimental results, the C-I bond dissociation on metcars has remained an unexplored problem in the theoretical and computational domains. Thus, the present investigation can fill in the gap and may also provide new insights provoking further developments in cluster and materials chemistry in future.

1 aSengupta, Turbasu1 aKhan, Muntazir, S.1 aPal, Sourav uhttps://library.ncl.res.in/content/mechanistic-investigation-carbon-iodine-bond-activation-niobium-carbon-cluster01900nas a2200181 4500008004100000022001400041245011100055210006900166260000800235490000700243520124500250100002201495700001801517700002201535700001801557700001601575856012701591 2018 eng d a2469-992600aCorrelation trends in the magnetic hyperfine structure of atoms: a relativistic coupled-cluster case study0 aCorrelation trends in the magnetic hyperfine structure of atoms  cAUG0 v983 a

The role of electron correlation in the hyperfine structure of alkali metals and alkaline earth metal monopositive ions in their ground electronic configuration is investigated using the Z-vector method in a relativistic coupled-cluster regime within the singles and doubles approximation. The systematic effects of core-correlating functions, polarization of core electrons, and high-lying virtual functions on core electrons correlation are studied. The study reveals that the core-correlating function plays a significant role in core polarization and thus is very important for precise calculation of the wave function near the nuclear region. The inner-core electrons (1s-2p) require very high virtual energy functions for proper correlation. Therefore, the all-electron correlation treatment and the inclusion of higher-energy virtual functions are the key factors for precise calculation of the hyperfine structure constant of atoms. Our calculated values are in excellent agreement with the available experimental values, which also implies that the wave function produced by the Z-vector method is accurate enough for further calculation of the parity- and time-reversal symmetry-violating properties in atoms and molecules.

1 aTalukdar, Kaushik1 aSasmal, Sudip1 aNayak, Malaya, K.1 aVaval, Nayana1 aPal, Sourav uhttps://library.ncl.res.in/content/correlation-trends-magnetic-hyperfine-structure-atoms-relativistic-coupled-cluster-case01431nas a2200193 4500008004100000022001500041245012700056210006900183260000800252300001600260490000700276520071800283100001801001700002501019700002601044700002701070700001601097856012401113 2018 eng d a 1463-907600aDissociative chemisorption of hydrogen molecules on defective graphene-supported aluminium clusters: a computational study0 aDissociative chemisorption of hydrogen molecules on defective gr cNOV a26506-265120 v203 a

Using periodic density functional theory-based calculations, in the present study, we address the chemical bonding between aluminium clusters (Al-n, n = 4-8 and 13) and monovacant defective graphene. The adsorption strength of the above-mentioned aluminium clusters is fivefold (approximate to 3 to 5 eV) higher on defective graphene as compared to the earlier reported values on non-defective graphene and BN-doped graphene. The Bader charge analysis and different charge densities reveal that this adsorption is driven by significant charge transfer from the Al clusters to defective graphene. Thus, chemisorbed Al clusters demonstrate high activity towards dissociative adsorption of molecular hydrogen.

1 aKumar, Deepak1 aGovindaraja, Thillai1 aKrishnamurty, Sailaja1 aKaliaperumal, Selvaraj1 aPal, Sourav uhttps://library.ncl.res.in/content/dissociative-chemisorption-hydrogen-molecules-defective-graphene-supported-aluminium01372nas a2200205 4500008004100000022001400041245009300055210006900148260000800217300001100225490000800236520069000244653001300934653002500947653001800972100002700990700001801017700001601035856011501051 2018 eng d a0020-760800aLower scaling approximation to EOM-CCSD: a critical assessment of the ionization problem0 aLower scaling approximation to EOMCCSD a critical assessment of  cJUL ae255940 v1183 a

In this article, we investigate the performance of different approximate variants of the EOM-CCSD method for calculation of ionization potential (IP), as compared to EOM-CCSDT reference values. None of the lower scaling approximations to the EOM-CCSD method give a consistent performance for valence, inner valence, and core ionization, favoring one, or the other depending on the nature of the approximation used. The parent EOMIP-CCSD method gives superior performance for valence IP but can show large errors for inner valence and core ionization. The problem is particularly severe for core-ionization, where even the EOMIP-CCSDT method cannot provide quantitative accuracy.

10aEOM-CCSD10aIonization potential10alower scaling1 aDutta, Achintya, Kumar1 aVaval, Nayana1 aPal, Sourav uhttps://library.ncl.res.in/content/lower-scaling-approximation-eom-ccsd-critical-assessment-ionization-problem01065nas a2200169 4500008004100000022001500041245011300056210006900169260000800238300001600246490000800262520043700270100002000707700002200727700001600749856013000765 2018 eng d a 1932-744700aSpecificity of amino acid-aluminum cluster interaction and subsequent oxygen activation by the above complex0 aSpecificity of amino acidaluminum cluster interaction and subseq cDEC a28310-283230 v1223 aAmino acid aluminum cluster complex has been shown to be a promising oxygen molecule activator and has the potential to dissociate O-O bond on the cluster surface. The study of the complex also reveals specificity of amino acid to aluminum cluster in the above complex, which can be used in the detection of amino acid. The results have been obtained by the density functional theory at the B3LYP/6-311++g(d,p) level of calculation.1 aSamanta, Bipasa1 aSengupta, Turbasu1 aPal, Sourav uhttps://library.ncl.res.in/content/specificity-amino-acid-aluminum-cluster-interaction-and-subsequent-oxygen-activation-above01511nas a2200241 4500008004100000022001400041245004700055210004600102260000800148300000600156490000700162520083900169653002201008653003401030653001801064653000801082653001901090653002401109100002001133700002201153700001601175856007801191 2019 eng d a1610-294000aAluminum cluster for CO and O-2 adsorption0 aAluminum cluster for CO and O2 adsorption cJAN a20 v253 a

Low temperature oxidation of CO to CO2 is an important process for the environment. Similarly adsorption of CO from the releasing sources is also of major concern today. Whereas the potential of gold and silver clusters is well proven for thecatalysis of the above mentioned reaction, the potential of aluminum (Al) clusters remains unexplored. The present study proves that, similar to the transition metals, Al clusters can also be used for adsorption of gases. We first tested the potential of Al cluster as adsorbents for CO. The high binding energy (BE) values prove that Al clusters can be used for adsorbing both CO and O-2. Since oxygen binding is more facile, we adsorbed oxygen on Al and then checked the effect of this O-2 on the BE of CO. The results were obtained by DFT calculations at M062X/TZVP level of theory.

10aAluminum clusters10aCharge decomposition analysis10aCO adsorption10aDFT10aO-2 adsorption10aWiberg bond indices1 aSamanta, Bipasa1 aSengupta, Turbasu1 aPal, Sourav uhttps://library.ncl.res.in/content/aluminum-cluster-co-and-o-2-adsorption01790nas a2200181 4500008004100000022001400041245008600055210006900141260000900210300001100219490000700230520118200237100002201419700002201441700001801463700001601481856011101497 2019 eng d a2469-992600aNuclear parity- and time-reversal-symmetry violation in the (HgH)-Hg-201 molecule0 aNuclear parity and timereversalsymmetry violation in the HgHHg20 cMAR  a0325030 v993 a

Investigation of the nuclear magnetic quadrupole moment (MQM) is an excellent way to reveal the new physics in the hadron sector of matter. Therefore, we investigate the violation of parity (P) and time-reversal (T) invariance induced by the MQM of the( 201) Hg nucleus in the HgH molecule, which has been proposed as a very promising candidate for the experimental search of the electric dipole moment of electron [M. G. Kozlov and A. Derevianko, Phys. Rev. Lett. 97, 063001 (2006)]. We report the precise value of the molecular parameter, W-M, associated with the P, T-odd nuclear MQM-electron interaction in (HgH)-Hg-201 using the four-component relativistic coupled-cluster method. This parameter is required to interpret the experimental P, T-odd frequency shift in terms of the MQM of nuclei. Furthermore, the magnetic hyperfine structure (HFS) constants of the molecule are computed at the same level of theory. We also study the role of core-correlating functions and the virtual energy functions in the calculations of the HFS constant and W-M. The most reliable value of W(M )in HgH is obtained as 3.22 x 10 (33) Hz/e cm (2) with an uncertainty of around 6%.

1 aTalukdar, Kaushik1 aNayak, Malaya, K.1 aVaval, Nayana1 aPal, Sourav uhttps://library.ncl.res.in/content/nuclear-parity-and-time-reversal-symmetry-violation-hgh-hg-201-molecule01816nas a2200157 4500008004100000245011000041210006900151260000800220490000800228520121300236100002201449700002201471700001801493700001601511856013101527 2019 eng d00aRelativistic coupled-cluster investigation of parity (P) and time-reversal (T) symmetry violations in HgF0 aRelativistic coupledcluster investigation of parity P and timere cFEB0 v1503 a

We employ the Z-vector method in the four-component relativistic coupled-cluster framework to calculate the parity (P) and time-reversal (T) symmetry violating scalar-pseudoscalar nucleus-electron interaction constant (W-s), the effective electric field (E-eff) experienced by the unpaired electron, and the nuclear magnetic quadrupole moment-electron interaction constant (W-M) in the open-shell ground electronic state of HgF. The molecular frame dipole moment and the magnetic hyperfine structure (HFS) constant of the molecule are also calculated at the same level of theory. The outcome of our study is that HgF has a high value of E-eff (115.9 GV/cm), W-s (266.4 kHz), and W-M (3.59 x 10(33) Hz/e cm(2)), which shows that it can be a possible candidate for the search of new physics beyond the standard model. Our results are in good agreement with the available literature values. Furthermore, we investigate the effect of the basis set and the virtual energy functions on the computed properties. The role of the high-energy virtual spinors is found to be significant in the calculation of the HFS constant and the P,T-odd interaction coefficients. Published under license by AIP Publishing.

1 aTalukdar, Kaushik1 aNayak, Malaya, K.1 aVaval, Nayana1 aPal, Sourav uhttps://library.ncl.res.in/content/relativistic-coupled-cluster-investigation-parity-p-and-time-reversal-t-symmetry-violations01378nas a2200181 4500008004100000022001400041245010800055210006900163260000800232300001100240490000800251520073600259100002200995700002201017700001801039700001601057856012301073 2020 eng d a0021-960600aElectronic structure parameter of nuclear magnetic quadrupole moment interaction in metal monofluorides0 aElectronic structure parameter of nuclear magnetic quadrupole mo cNOV a1843060 v1533 a

The electronic structure parameter (W-M) of the nuclear magnetic quadrupole moment (MQM) interaction in numerous open-shell metal monofluorides (viz., MgF, CaF, SrF, BaF, RaF, and PbF) is computed in the fully relativistic coupled-cluster framework. The electron-correlation effects are found to be very important for the precise calculation of W-M in the studied molecular systems. The molecular MQM interaction parameter scales nearly as Z(2) in the alkaline earth metal monofluorides, where Z is the nuclear charge of metal. Our study identifies (RaF)-Ra-223 as a good candidate for the experimental search of the nuclear MQM, which can help unravel the physics beyond the standard model in the hadron sector of matter.

1 aTalukdar, Kaushik1 aNayak, Malaya, K.1 aVaval, Nayana1 aPal, Sourav uhttps://library.ncl.res.in/content/electronic-structure-parameter-nuclear-magnetic-quadrupole-moment-interaction-metal01908nas a2200181 4500008004100000022001400041245007000055210006700125260000800192300001600200490000800216520132900224100002401553700001501577700001601592700001801608856010001626 2020 eng d a1089-563900aNegative ion resonance states: the fock-space coupled-cluster way0 aNegative ion resonance states the fockspace coupledcluster way cDEC a10407-104210 v1243 a

The negative ion resonance states, which are electron-molecule metastable compound states, play the most important role in free-electron controlled molecular reactions and low-energy free-electron-induced DNA damage. Their electronic structure is often only poorly described but crucial to an understanding of their reaction dynamics. One of the most important challenges to current electronic structure theory is the computation of negative ion resonance states. As a major step forward, coupled-cluster theories, which are well-known for their ability to produce the best approximate bound state electronic eigen solutions, are upgraded to offer the most accurate and effective approximations for negative ion resonance states. The existing Fock-space coupled-cluster (FSCC) and the equation-of-motion coupled-cluster (EOM-CC) approaches that compute bound states are redesigned for the direct and simultaneous determination of both the kinetic energy of the free electron at which the electron-molecule compound states are resonantly formed and the corresponding autodetachment decay rate of the electron from the metastable compound state. This Feature Article reviews the computation of negative ion resonances using the FSCC approach and, in passing, provides the highlights of the equivalent EOM-CC approach.

1 aBasumallick, Suhita1 aSajeev, Y.1 aPal, Sourav1 aVaval, Nayana uhttps://library.ncl.res.in/content/negative-ion-resonance-states-fock-space-coupled-cluster-way01799nas a2200217 4500008004100000022001400041245007200055210006900127260000800196300001100204490000700215520109000222653004301312653002501355653002501380100002201405700002201427700001801449700001601467856009801483 2020 eng d a0953-407500aRelativistic coupled-cluster study of BaF in search of CP violation0 aRelativistic coupledcluster study of BaF in search of CP violati cJUL a1351020 v533 a

BaF is one of the potential candidates for the experimental search of the electric dipole moment of the electron (eEDM). The NL-eEDM collaboration is building a new experimental set up to measure the eEDM using the BaF molecule (The NL-eEDM collaboration, 2018 Eur. Phys. J. D 72: 197). To analyze the results of such an experiment, one would require the accurate value of the molecular P, T-odd interaction parameters that cannot be measured from any experiment. In this work, we report the precise value of the P, T-odd interaction parameters of the BaF molecule obtained from the four-component relativistic coupled-cluster calculations. We also calculate the hyperfine structure (HFS) constants of the same molecule to assess the reliability of the reported molecular parameters. The calculated HFS constants show good agreement with the available experimental values. Further, the systematic effects of electron-correlation along with the roles of inner-core electrons and the virtual energy functions in the calculation of the studied properties of BaF are investigated.

10aelectric dipole moment of the electron10aelectron-correlation10aRelativistic effects1 aTalukdar, Kaushik1 aNayak, Malaya, K.1 aVaval, Nayana1 aPal, Sourav uhttps://library.ncl.res.in/content/relativistic-coupled-cluster-study-baf-search-cp-violation01866nas a2200205 4500008004100000022001400041245012500055210006900180260000800249300001100257490000800268520113700276100002001413700001801433700002201451700002201473700001801495700001601513856013101529 2020 eng d a0021-960600aRelativistic double-ionization equation-of-motion coupled-cluster method: application to low-lying doubly ionized states0 aRelativistic doubleionization equationofmotion coupledcluster me cMAR a1043020 v1523 a

This article deals with the extension of the relativistic double-ionization equation-of-motion coupled-cluster (DI-EOMCC) method [H. Pathak et al. Phys. Rev. A 90, 010501(R) (2014)] for the molecular systems. The Dirac-Coulomb Hamiltonian with four-component spinors is considered to take care of the relativistic effects. The implemented method is employed to compute a few low-lying doubly ionized states of noble gas atoms (Ar, Kr, Xe, and Rn) and Cl-2, Br-2, HBr, and HI. Additionally, we presented results with two intermediate schemes in the four-component relativistic DI-EOMCC framework to understand the role of electron correlation. The computed double ionization spectra for the atomic systems are compared with the values from the non-relativistic DI-EOMCC method with spin-orbit coupling [Z. Wang et al. J. Chem. Phys. 142, 144109 (2015)] and the values from the National Institute of Science and Technology (NIST) database. Our atomic results are found to be in good agreement with the NIST values. Furthermore, the obtained results for the molecular systems agree well with the available experimental values.

1 aPathak, Himadri1 aSasmal, Sudip1 aTalukdar, Kaushik1 aNayak, Malaya, K.1 aVeval, Nayana1 aPal, Sourav uhttps://library.ncl.res.in/content/relativistic-double-ionization-equation-motion-coupled-cluster-method-application-low-lying01561nas a2200181 4500008004100000022001400041245011000055210006900165260000900234300001100243490000800254520091100262100002201173700002201195700001801217700001601235856012801251 2020 eng d a2469-992600aRole of electron correlation in the P, T-odd effects of CdH: a relativistic coupled-cluster investigation0 aRole of electron correlation in the P Todd effects of CdH a rela cMAR  a0325050 v1013 a

We investigate the parity (P) and time-reversal (T) symmetry violating effects in the CdH molecule and perform the relativistic coupled-cluster calculation of the molecular parameters-E-eff, W-s, and W-M-related to the electric dipole moment of electron (eEDM) interaction, the scalar-pseudoscalar (S-PS) nucleus-electron neutral current coupling, and the nuclear magnetic quadrupole moment (MQM) interaction with electrons, respectively. We also compute the molecular dipole moment and the magnetic hyperfine structure coupling constant of CdH. The values of E-eff, W-s, and W-M obtained by us in the said molecule are 12.2 GV/cm, 14.0 kHz, and 0.82 x 10(33) Hz/e cm(2), respectively, within an uncertainty of 10%. Furthermore, we study the trend of electron-correlation in the computed properties of CdH and that of the P, T-odd parameters in the group-12 monohydrides (i.e., ZnH, CdH, and HgH).

1 aTalukdar, Kaushik1 aNayak, Malaya, K.1 aVaval, Nayana1 aPal, Sourav uhttps://library.ncl.res.in/content/role-electron-correlation-p-t-odd-effects-cdh-relativistic-coupled-cluster-investigation01675nas a2200241 4500008004100000022001400041245009400055210006900149260000900218490000800227520077000235653006901005653003901074653002001113653005701133653002001190100002401210700002701234700001601261700001801277700001601295856012201311 2020 eng d a0026-897600aShape resonance of sulphur dioxide anion excited states using the CAP-CIP-FSMRCCSD method0 aShape resonance of sulphur dioxide anion excited states using th cAUG 0 v1183 a

We have studied the shape resonance of excited states of sulphur dioxide (SO2) anion by using the correlated independent particle Fock space multi-reference coupled cluster (CAP-CIP-FSMRCCSD) method augmented by complex absorption potential. These resonant states have been trapped experimentally in recent years by electron collision. In particular, we have investigated e(-)-SO2 scattering and computed the negative-ion resonance states of the anion responsible for the two resonances around 4.45 and 6.56 eV and compared the results with the existing experimental observations. From the computational results using the CAP-CIP-FSMRCCSD method, it has been observed that both the resonances near 4.45 and 6.56 eV result from A(1) symmetries. [GRAPHICS] .

10aCAP augmented correlated independent particle (CAP-CIP-FSMRCCSD)10acomplex absorption potential (CAP)10acoupled cluster10aFock space multireference coupled cluster (FSMRCCSD)10ashape resonance1 aBasumallick, Suhita1 aBhattacharya, Sumantra1 aJana, Irina1 aVaval, Nayana1 aPal, Sourav uhttps://library.ncl.res.in/content/shape-resonance-sulphur-dioxide-anion-excited-states-using-cap-cip-fsmrccsd-method01653nas a2200217 4500008004100000022001400041245014100055210006900196260000800265300001300273490000800286520083500294653002501129653004701154653001501201653003801216100001701254700001601271700001801287856013001305 2021 eng d a0026-897600aInteratomic Coulombic decay in Neon-Helium cluster: a complex absorbing potential based equation-of-motion coupled cluster investigation0 aInteratomic Coulombic decay in NeonHelium cluster a complex abso cMAY ae18843000 v1193 a

The interatomic Coulombic decay (ICD) of the Ne(2s(-1)) and Ne(2s(-1)2p(-1)) states in neon-helium dimer is studied using highly accurate complex absorbing potential based equation-of-motion coupled cluster (CAP-EOMCC) method. The ICD decay process for the Ne(2s(-1)) state in neon-helium dimer is closed at its equilibrium bond distance. However, the decay channel is open at large bond distance of 6.2 angstrom. The decay channel for the double ionised Ne(2s(-1)2p(-1)) state is open at 3.46 angstrom. From our calculations, we have noticed that the decay rate of Ne(2s(-1)2p(-1)) state in neon-helium dimer is four times faster compared to the Ne(2s(-1)) state. We have also investigated how the decay rate of Ne(2s(-1)) state in neon-helium cluster varies in the presence of different helium environment. [GRAPHICS] .

10adouble ionised state10aequation-of-motion coupled cluster (EOMCC)10aHe droplet10ainteratomic Coulombic decay (ICD)1 aGhosh, Aryya1 aPal, Sourav1 aVaval, Nayana uhttps://library.ncl.res.in/content/interatomic-coulombic-decay-neon-helium-cluster-complex-absorbing-potential-based-equation01585nas a2200253 4500008004100000022001400041245014100055210006900196260000800265300001100273490000800284520070400292653003200996653002201028653001601050653002701066653002001093653001501113100001601128700002401144700001601168700001801184856012901202 2021 eng d a0020-760800aResonance study: effect of partial triples excitation using complex absorbing potential-based Fock-space multi-reference coupled cluster0 aResonance study effect of partial triples excitation using compl cSEP ae267380 v1213 a

Resonances are metastable states with finite lifetime. They play important role in physics, chemistry and biology. The theoretical calculation of resonance state is a challenging problem. In this paper we have studied the shape resonance of Be, Mg, N-2 and CO. We have used correlated independent particle approximation to the Fock space multi-reference coupled cluster singles-doubles with third-order triples (CAP-CIP-FSMRCCSD(T)) method augmented by complex absorption potential. The resonance energy and decay widths are obtained by solving a non-Hermitian eigen-value problem within FSMRCC framework. The effects of the lowest order triples on the resonance energy and decay are studied.

10acomplex absorbing potential10aelectron affinity10aFock&\#820810anegative ion resonance10apartial triples10aspace MRCC1 aJana, Irina1 aBasumallick, Suhita1 aPal, Sourav1 aVaval, Nayana uhttps://library.ncl.res.in/content/resonance-study-effect-partial-triples-excitation-using-complex-absorbing-potential-based01793nas a2200253 4500008004100000022001400041245010000055210006900155260000800224300000700232490000800239520093800247653002701185653001701212653002401229653002701253653002501280100002201305700002801327700002501355700001801380700001601398856012501414 2023 eng d a1432-881X00aRelativistic coupled-cluster study of SrF for low-energy precision tests of fundamental physics0 aRelativistic coupledcluster study of SrF for lowenergy precision cFEB a150 v1423 a

SrF, being a laser-coolable molecule, can be an interesting system for spectroscopic tests of fundamental physics. We present an electronic structure study of this molecule within the four-component relativistic coupled-cluster singles and doubles (RCCSD) framework and employ the RCCSD-based methods to compute its molecular-frame dipole moment and core properties such as hyperfine structure coupling constant and molecular P, T-odd electronic structure parameters that are of great importance for the high-precision tests of fundamental physics. The impact of basis set size, Hamiltonian and nuclear model on the property calculation of SrF is also investigated. The computed results are in good agreement with the available experimental values. The present study shows that the SrF molecule could be useful for high-precision molecular experiments to explore physics beyond the Standard Model of elementary particles.

10aCoupled cluster theory10aCP violation10aHyperfine structure10aMolecular spectroscopy10aRelativistic effects1 aTalukdar, Kaushik1 aBuragohain, Haimyapriya1 aNayak, Malaya, K. K.1 aVaval, Nayana1 aPal, Sourav uhttps://library.ncl.res.in/content/relativistic-coupled-cluster-study-srf-low-energy-precision-tests-fundamental-physics01944nas a2200181 4500008004100000022001400041245011500055210006900170260000800239300001400247490000700261520128600268100002201554700002201576700001801598700001601616856013001632 2025 eng d a1549-961800aRelativistic extended-coupled-cluster calculations of P , T -odd sensitivity parameters for diatomic molecules0 aRelativistic extendedcoupledcluster calculations of P T odd sens cMAY a5481-54890 v213 a

We demonstrate the first application of the four-component relativistic extended-coupled-cluster (ECC) method, a variational approach, to determine the P , T -odd molecular electronic structure parameters necessary for high-precision spectroscopic measurements on ultracold molecules. We calculate the P , T -odd sensitivity parameters for two moderately heavy, laser-coolable diatomic molecules (SrH and SrF), as well as two relatively lighter open-shell molecules (CaH and CaF) in their ground electronic state, 2 Sigma 1/2. The hyperfine structure constants of 87Sr in the SrF and SrH molecules are also computed and compared with available experimental results to assess the accuracy of our calculations. Furthermore, we examine the roles of electron correlation, relativity, basis set, and virtual spinors in ECC calculations of the sensitivity parameters. Our study reveals that the ECC method is a reliable technique for studying P , T -odd properties of diatomic molecules such as CaH, CaF, SrH and SrF, yielding results in very good agreement with those obtained using two widely employed analytic approaches: the Z-vector technique and the linear expectation-value method within the relativistic single-reference coupled-cluster singles and doubles framework.

1 aTalukdar, Kaushik1 aNayak, Malaya, K.1 aVaval, Nayana1 aPal, Sourav uhttps://library.ncl.res.in/content/relativistic-extended-coupled-cluster-calculations-p-t-odd-sensitivity-parameters-diatomic