The dynamics of H2 dissociation on Cu and Ni surfaces. Mixed quantum-classical studies with all degrees of freedom

The dissociative adsorption of hydrogen on metals is examined using models which contain all six molecular degrees of freedom. Fully classical studies are implemented, as well as a mixed approach in which three degrees of freedom are treated quantum mechanically, and three classically. Probabilities for dissociation and rovibrational excitation are computed as a function of incident translational energy for both H2 and D2 on a reactive Ni surface and a less reactive Cu surface. Two sudden approximations are tested, in which either the center of mass translation parallel to the surface or the azimuthal orientation of the molecule are frozen. The quantum and classical results are compared for the above cases.