01566nas 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<p>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.</p>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-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<p>{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</p>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-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<p>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.</p>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-0