Potential energy surfaces of SimOn cluster formation and isomerization

2020-03-17 00:45:07

energy potential cluster formation states

责任者: Avramov, P.V.;Adamovic, I.;Kai-Ming Ho;Wang, C.Z.;Lu, W.C.;Gordon, M.S. 单位: Dept. of Chem., Iowa State Univ., Ames, IA, USA 来源出处: Journal of Physical Chemistry A(J. Phys. Chem. A (USA)),2005/07/21,109(28):6294-302 摘要: The reaction paths for formation and isomerization of a set of silica SimOn (m = 2,3, n = 1-5) nanoclusters have been investigated using second-order pertubation theory (MP2) with the 6-31G(d) basis set. The MP2/6-31G(d) calculations have predicted singlet ground states for all clusters excluding Si3O2. The total energies of the most important points on the potential energy surfaces (PES) have been determined using the completely renormalized (CR) singles and doubles coupled cluster method including perturbative triples, CR-CCSD(T) with the cc-pVTZ basis set. Although transition states have been located for many isomerization reactions, only for Si3O3 and Si3O4 have some transition states been found for the formation of a cluster from the separated reactants. In all other cases, the process of formation of SimOn clusters appears to proceed without potential energy barriers 关键词: coupled cluster calculations;ground states;isomerisation;molecular clusters;perturbation theory;potential energy surfaces;reaction kinetics;silicon compounds;potential energy surface;SimOn cluster formation;nanocluster formation;isomerization reaction;silica nanocluster;second-order pertubation theory;MP2 calculation;coupled cluster method;transition states;potential energy barriers;Si2O;Si2O2;Si2O3;Si2O4;Si2O5;Si3O;Si3O2;Si3O3;Si3O4;Si3O5