Investigation of Differential Cross Sections for H+HDS(υ_HS=0,1)→H₂+DS Reactions

Employing the potential-averaged five-dimensional time-dependent wave-packet approach, we have obtained the first fully converged state-to-state differential cross sections for the H+HDS→H₂+DS reaction, with the non-rotating HDS reactant prepared in both its ground state and v_HS=1 vibrational excitation. Our calculations reveal that the vibrationally excited reaction exhibits a larger total integral cross section than its ground state counterpart when the total energy exceeds 0.48 eV —much lower than the 0.75 eV crossover energy observed in the H+H₂S(100)(001)→H₂+SH reactions. Moreover, the product H₂ vibrational state distributions for the H+HDS(v_HS=1) reaction are hotter compared to those of H+H₂S(100)(001). These phenomena arise from the difference between stretching mode excitation and bond excitation in the reactant molecules, despite the vibrational excitation energy being the same. On the other hand, the angular distribution behavior for the H+HDS(v_HS=1) reaction is quite similar to those of the H+H₂S(100)(001) reaction.