An Empirical Dynamical Barrier for Statistical Theory of Low-Energy Reactive S(1D) + HD(j = 0), H2(j = 0) Collisions

Dynamics study on the non-adiabatic Na(3p) + HD → NaH/NaD + D/H reaction: insertion-abstraction mechanism

Time-dependent wave packet calculations are carried out for two reaction channels of the non-adiabatic Na(3p) + HD → NaH/NaD + D/H reaction. The potential well on the excited state potential energy surface makes the reaction preferable to proceed through the insertion reaction path. The dominance of the NaD + H reaction channel and product rotational state distributions are found to be in agreement with the characteristics of typical adiabatic insertion reactions. However, significant forward scattering peaks in the differential cross sections (DCS) are found to be inconsistent with the forward-backward symmetric scattering characteristic of typical adiabatic insertion reactions, which indicate that the Na(3p) + HD reaction is dominated by a direct reaction mechanism. The comparison between adiabatic and non-adiabatic calculated DCSs reveals that the non-adiabatic couplings in the reaction could reduce the lifetime of the intermediate complex. Finally, the insertion-abstraction mechanism is put forward for the non-adiabatic Na(3p) + HD reaction.

A Mixed Quantum/Classical Approach to Associative Detachment in Low-Energy H- + H Collisions

A theoretical approach, in which the rotational degrees of freedom are treated quantum mechanically while translational degrees of freedom classically or semiclassically, is applied to calculate the total and final-state specific cross sections for the reaction H^- + H → H₂( v, j) + e^- in the range of low collision energies ( E = 1-754 meV). The calculated cross sections agree well with the existing experimental and theoretical results. Results are also presented for the inverse dissociative attachment process: H₂( v, j) + e^- → H^- + H.