Classical mechanical investigation of collinear H⁻+H₂→H₂+H⁻ dynamics

Abstract

We report the results of a quasiclassical trajectory investigation of the reaction probability (P^R) as a function of relative translational energy for the title reaction, with H₂ in its ground vibrational state (v=0) in collinear geometry on the Stärck-Meyer ab initio potential energy surface and compare them with quantum mechanical results. Results for H⁻, D₂ collisions under identical conditions are compared with experimental results. The nature of the dynamics is investigated by examining the dependence of final vibrational action on the initial vibrational phase (φ_i) and by examining Poincaré surface of section plots for individual trajectories in hyperbolic coordinates. It is found that the dynamics is regular when P^R is either zero or unity. But when 0<P^R<1, some of the trajecteries are regular and some are chaotic in behavior.