HOW STEEPLY CURVED REACTION PATHS INFLUENCE DISSOCIATION AND VIBRATIONAL-EXCITATION PROCESSES

We investigate dynamical effects related to the dissociative adsorptio n and the vibrational excitation of H-2 molecules scattering from a me tal surface. Recent total energy calculations have found that activati on barriers can be rather late along the reaction path, and that the g eometry of the transition state can be skewed with respect to the surf ace. We have designed a set of model 2-dimensional potentials based on recent ab initio results and have performed time-dependent quantum si mulations on them. We show how the change in the curvature of the pote ntial can significantly effect the dissociation and vibrational excita tion.