Comparison of reactive and inelastic scattering of H2+D2 using four semiempirical potential energy surfaces

Abstract

Collisions between hydrogen and deuterium molecules are examined using quasiclassical dynamical trajectory calculations with the intermolecular field specified by four semiempirical potential energy surfaces. Three of the surfaces are calculated within the valence bond model with semiempirical evaluation of the integrals, and the fourth is the London type. Various degrees of agreement are observed between these four surfaces and ab initio results. The trajectory calculations are performed at high system energies to permit the possibility of reactions. In addition to nonreactive collisions, four reaction paths are found on each surface with the product species 2H+D2, H2+2D, HD+H+D, and 2HD. The results are analyzed to determine the effect of surface properties on reaction probabilities, average final state properties of the molecules and average final state energy distributions. Dynamical results are found to be strongly dependent on surface characteristics.