Analysis of the 2M approximation in the stochastic treatment of some V-V and V-T collision problems

Abstract Markovian and non-markovian master equations of various orders were solved for collinear V-V collisions between H 2 + M (M = H 2 , N 2 , Cl 2 , HCl, CO, ClH) diatomic systems. For completeness, the V-T energy exchange in collisions of the H 2 + A (A = H, He, Ne, Ar) atom-diatom systems has also been included. Calculated representative transition probabilities suggest that in the V-V case the second-order markovian (2M) approximation is valid in a much wider collision energy range than in the V-T case. Some rules governing the 2M approximation have also been found. The results presented in the paper exhibit a show convergence of the probabilities versus the perturbation expansion of the potential.