@article { ISI:000239884300028, title = {Theoretical study of N2O reduction by CO in Fe-BEA zeolite}, journal = {Chemphyschem}, volume = {7}, number = {8}, year = {2006}, month = {AUG}, pages = {1795-1801}, publisher = {WILEY-V C H VERLAG GMBH}, type = {Article}, address = {PO BOX 10 11 61, D-69451 WEINHEIM, GERMANY}, abstract = {

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.

}, keywords = {Density functional calculations, iron, nitrogen oxides, reaction mechanisms, zeolites}, issn = {1439-4235}, doi = {10.1002/cphc.200600228}, author = {Fischer, Gerd and Goursot, Annick and Coq, Bernard and Delahay, Gerard and Pal, Sourav} } @article { ISI:000310567800027, title = {Theoretical study of frequency and temperature dependence of dipole-quadrupole polarizability of P-4 and adamantane}, journal = {Chemical Physics Letters}, volume = {552}, year = {2012}, month = {NOV}, pages = {146-150}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

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.

}, issn = {0009-2614}, doi = {10.1016/j.cplett.2012.09.045}, author = {Shedge, Sapana V. and Pal, Sourav and Koester, Andreas M.} } @article { ISI:000375969000054, title = {Transition metal doped aluminum clusters: an account of spin}, journal = {Journal of Physical Chemistry C}, volume = {120}, number = {18}, year = {2016}, month = {MAY}, pages = {10027-10040}, publisher = {AMER CHEMICAL SOC}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

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.

}, issn = {1932-7447}, doi = {10.1021/acs.jpcc.6b00510}, author = {Sengupta, Turbasu and Das, Susanta and Pal, Sourav} }