01516nas 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-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-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-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-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-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-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-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-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-001296nas 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-functionalinvestigation01900nas 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-case