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Indexed by:期刊论文

Date of Publication:2015-05-07

Journal:PHYSICAL CHEMISTRY CHEMICAL PHYSICS

Included Journals:PubMed、SCIE、Scopus

Volume:17

Issue:17

Page Number:11732-11739

ISSN No.:1463-9076

Abstract:A new global potential energy surface (PES) is obtained for the ground electronic state of the LiH2 system based on high-level energies. The energy points are calculated at the multireference configuration interaction level with aug-cc-pVXZ (X = Q, 5) basis sets, and these energies are extrapolated to the complete basis set limit. The neural network method and hierarchical construction scheme are applied in the fitting process and the root mean square error of the fitting result is very small (0.004 eV). The dissociation energies and equilibrium distances for LiH(X-1 Sigma(+)) and H-2(X-1 Sigma(+)(g)) obtained from the new PES are in good agreement with the experimental data. On the new PES, time-dependent wave packet studies for the H(S-2) + LiH(X-1 Sigma(+)) -> Li(S-2) + H-2(X-1 Sigma(+)(g)) reaction have been carried out. In this reaction, no threshold is found due to the absence of an energy barrier on the minimum energy path. The calculated integral cross sections are high at low collision energy and will decrease with the increase of the collision energy. The product molecule H-2 tends to be forward scattering due to direct reactive collisions, which becomes more evident at higher collision energies.