Theoretical study of S + SH reaction on its ground state HS2(X2 A ″) potential energy surface

Abstract

ABSTRACT In this study, we explore the initial state selected dynamics of the S + SH ( X 2 Π ) → S 2 ( X 3 ∑ ) + H reaction through the lens of time-dependent quantum dynamics (QD), quasi-classical trajectory (QCT), and statistical quantum mechanical (SQM) approaches, utilising the electronic ground state HS 2 (X 2 A ′′ ) potential energy surface (PES). We present total reaction probabilities and integral cross sections (ICSs) as part of our findings. Our results indicate that at low and moderate collision energies, the reaction predominantly follows an indirect pathway, forming meta-stable quasi-bound complexes. Additionally, we observe that the rotational excitation of the SH reagent initially leads to a decrease and then an increase in reactivity. We conduct a comprehensive analysis and comparison of the outcomes from QD, QCT, and SQM methodologies.