01124nas 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-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-001926nas a2200169 4500008004100000022001400041245011900055210006900174260000900243300001100252490000800263520130400271100001601575700001701591700001801608856013001626 2023 eng d a0021-960600aEffect of charge and solvation shell on non-radiative decay processes in s-block cationic metal ion water clusters0 aEffect of charge and solvation shell on nonradiative decay proce cAUG  a0543040 v1593 a

Intermolecular Coulombic decay or electron transfer-mediated decay are the autoionization processes through which a molecule can relax. This relaxation is only possible if the inner valence's ionization potential (IP) exceeds the system's double ionization potential (DIP). To study the effects of charge and solvation shell, we have calculated the IP, DIP values, and lifetime of Na-2s and Mg-2s temporary bound states in various optimized structures of Na+-(H2O)(n) and Mg2+-(H2O)(n) (n = 1-5) micro-solvated clusters, where n water molecules are distributed in a way that some are directly bound to the metal ion and the rest to the water molecules. The first and second solvation shells are the names for the former and the latter water-binding positions, respectively. For a given n, the lifetime of decaying states is longer when water molecules are in the second solvation shell. We found that the Mg-2p state can decay for all n values in Mg2+-(H2O)(n) clusters, whereas the Na-2p state's decay is possible for n >= 2 in Na+-(H2O)(n) clusters. Our findings highlight the influence of metal ions' charge, different solvation shell structures, and the number of water molecules on the decay rate. These systems are relevant to the human body, which makes this study significant.

1 aKumar, Ravi1 aGhosh, Aryya1 aVaval, Nayana uhttps://library.ncl.res.in/content/effect-charge-and-solvation-shell-non-radiative-decay-processes-s-block-cationic-metal-ion01858nas a2200265 4500008004100000022001400041245009300055210006900148260000800217300001500225490000700240520100900247653002401256653002401280653000801304653002701312653001801339100001701357700002501374700001601399700001701415700001701432700001901449856012401468 2023 eng d a2192-650600aEnhancing diradical character of chichibabin's hydrocarbon through fluoride substitution0 aEnhancing diradical character of chichibabins hydrocarbon throug cAUG ae2023002730 v883 a

In this work, 5-SIDipp [SIDipp=1,3-bis(2,6-diisopropylphenyl)-imidazolin-2-ylidene] (1) derived Chichibabin's hydrocarbon with an octafluorobiphenylene spacer (3) has been reported. The addition of two equivalents of 5-SIDipp with decafluorobiphenyl in presence of BF3 gives the double C-F bond activated imidazolium salt with two tetrafluoroborate anions, 2. Further reduction of 2 gives the fluorine substituted 5-SIDipp based Chichibabin's hydrocarbon, 3. Quantum chemical calculations suggested a singlet state of 3 with a singlet-triplet energy gap (?ES-T) of 3.7 kcal mol(-1), which is substantially lower with respect to the hydrogen substituted NHC-based Chichibabin's hydrocarbons (10.7 kcal mol(-1), B3LYP). As a result, the diradical character (y) of 3 (y=0.62) is also noticeably higher than the hydrogen substituted CHs (y=0.41-0.43). The ?ES-T was found to be higher in CASSCF (22.24 kcal mol(-1)) and CASPT2 (11.17 kcal mol(-1)) for 3 and the diradical character (d) is 44.6 %.

10aC-F Bond Activation10aChichibabin & PRIME10aDFT10aN-Heterocyclic carbene10as Hydrocarbon1 aKundu, Gargi1 aDash, Soumya, Ranjan1 aKumar, Ravi1 aVanka, Kumar1 aGhosh, Aryya1 aSen, Sakya, S. uhttps://library.ncl.res.in/content/enhancing-diradical-character-chichibabins-hydrocarbon-through-fluoride-substitution