The global potential energy surface of the RbH2 system and dynamics studies of the H + RbH → Rb + H2 reaction

Abstract

A new global potential energy surface of the ground state of the RbH2system is constructed by using the permutation invariant polynomial neural network method.In the ab initiocalculations, the aug-cc-pVQZ basis set for H, Def2-QZVPP basis set for Rb, and multi-reference configuration interaction method with Davidson correction are used. The topographical features of the new PES are discussed in detail, and no wells and barriers in the minimum energy path are found. Thereafter, specific initial-state dynamics calculations of the H + RbH (v = 0 ∼ 2,j = 0) → Rb + H2reaction are carried out based on the new PES by means of the time-dependent quantum wave packet method with a second-order split operator. The dynamics results indicate that the vibrational excitation of RbH molecules reduces and increases the reaction probability when the collision energy is below 0.4 eV and above 0.4 eV, respectively.