Quasi-classical trajectory study of the reaction H′ + HS on a new ab initio potential energy surface H2S (3A″)

Abstract

Theoretical study on the dynamics of reactions H′ + HS(v = 0, j = 0)→H2 + S and H′ + HS(v = 0, j = 0)→H + H′S is performed with quasi-classical trajectory (QCT) method on a new ab initio potential energy surface for the lowest triplet state of H2S (3A″) constructed in 2012 by Lv et al. The QCT-calculated reaction integral cross-sections are in good agreement with previous quantum wave packet results over the collision energy range of 0–50 kcal/mol. Both the abstraction and exchange reactions are governed by direct reaction dynamics and the trajectories follow the minimum energy path. The rotational angular momentum vector j′ of products in the two reaction channels are not only aligned perpendicular to scattering plane but also oriented along the negative direction of the axis perpendicular to the scattering plane. With the increase in collision energy, the variation trends of product polarization in the two reaction channels are different and that may be attributed to the obviously different characteristic of the two channels on the potential energy surface. Alignment and orientation of the product rotational angular momentum vector j′ of the abstraction reaction H′ + HS(v = 0, j = 0)→H2 + S and the exchange reaction H′ + HS(v = 0, j = 0)→H + H′S.