Mode specific dynamics in the H2 + SH → H + H2S reaction.

Full-dimensional coupled-channel quantum scattering and quasi-classical trajectory calculations have been carried out and analyzed to unravel the mode specific dynamics in the H2 + SH → H + H2S reaction employing two different accurate neural network representations of an ab initio global potential energy surface at the coupled cluster level. Strong mode selectivity was found and partially rationalized by the sudden vector projection model. Specifically, the vibrational excitation of H2 remarkably enhances the reactivity while its rotational excitation only slightly promotes the reaction. On the other hand, the reactant SH acts as a good spectator, whose vibrational and rotational excitations have a negligible effect on the reaction.