Simplified Classical Trajectory Model of Dissociative Scattering on Surfaces: Role of Incident Vibrational and Translational Energies

Abstract

Recently reported molecular ion/surface scattering experiments suggest that translational and vibrational energies each have a distinct influence on molecular dissociation for the NO+/GaAs(110) system [J. Chem. Phys. 1994, 100, 6791]. To interrogate the coupling between vibrational and translational degrees of freedom, classical trajectory simulations were performed. The dissociation dynamics and energy transfer processes were examined for three different molecule/surface repulsive potentials: a Born−Mayer potential, a Ziegler−Biersack−Littmark potential, and a Hartree−Fock potential. In each case, the calculated product appearance thresholds and average product translational energies are qualitatively consistent with the aforementioned experimental results. In all, this suggests that translational energy activates dissociation via a collision-induced dissociation mechanism. Regarding initial molecular vibrational energy, the classical model shows that the relative dissociation probability depends on vib...