Exact quantum dynamics study of the H(2S)+SiH+(X1Σ+) reaction on a new potential energy surface of SiH 2+(X2A1) *

Abstract

Based on a new global potential energy surface of SiH 2 + ( X 2 A 1 ) , the exact quantum dynamical calculation for the H(2 S) + SiH+(X1Σ+) → H2 + Si+ reaction has been carried out by using the Chebyshev wave packet method. The initial state specified (ν i = 0, j i = 0) probabilities, integral cross sections (ICS) and thermal rate constants of the title reaction are calculated. All partial wave contributions up to J = 90 are calculated in exact quantum calculation including the full Coriolis coupling (CC) effect. The dynamical behaviors of probabilities, ICSs and rate constants are found to be in accord with an exothermic reaction without potential barrier. By comparing the probabilities of CC with the corresponding centrifugal sudden (CS) approximation ones, it can be concluded that neglecting CC effect will decrease the collision time, increase the amplitude of oscillation and lead to overestimation or underestimation of the reaction probability. For ICSs and rate constants, it is found that the deviation of CC and CS ICSs is small in the most of collision energy range except for the range of 0 eV–0.05 eV, while the deviation of both rate constants is considerable in the temperature range of 16 K–1000 K.