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

We report the results of a quasiclassical trajectory investigation of the reaction probability (PR) 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 (φi) and by examining Poincaré surface of section plots for individual trajectories in hyperbolic coordinates. It is found that the dynamics is regular when PR is either zero or unity. But when 0<PR<1, some of the trajecteries are regular and some are chaotic in behavior.