Quasiclassical trajectory study of Li₂ (v≤25,j≤100)-Na exchange reaction

Abstract

The effect of high initial vibrational (v=0-25) and rotational (j=0-100) excitation of the reactant molecule on the cross-section σ^R for the reaction Li₂+Na→LiNa+Li at a relative translational energy (E_trans) of 0.5 eV has been investigated using the three-dimensional quasiclassical trajectory method on the recently proposed Varandas-Morais-Pais (VMP) potential. σ^R increases almost linearly with increase in v, but it remains unaltered, within the statistical error, with increase in j for j=0-30. For the higher j states, there is an increase in σ^R with increase in j, and the rotational enhancement gets larger with increase in v, becoming comparable to the vibrational enhancement at v=20. The dependence of σ^R on E_trans over the range 0.18-0.85 eV has been examined for v=0, j=0. For E_trans≤0.25 eV, all trajectories get trapped. For higher E_trans, σ^R rises to a maximum and then levels off. Comparison of our results with those on the Whitehead-Grice (WG) potential reveals that the reactivity is larger on the VMP potential than on the WG for the low v while the opposite is true for the higher v.