Inelastic gas-surface scattering. II. Results

Helium and molecular-hydrogen scattering from copper is calculated to examine general features of scattering for these systems, especially the quantum mechanics of the scattering process, both for the motion of the particle and the excitations of the lattice. These calculations use an interaction potential chosen to simplify the numerical calculation while retaining the essential physics of the interaction. He-scattering calculations show that these approximations quantitatively reproduce experimental results. Based on this success, we show how the scattering probabilities depend on details of the system like the well depth and the steepness of the potential as well as the assumptions made to simplify the interaction potential. ${\mathrm{H}}_2$ and ${\mathrm{D}}_2$ inelastic scattering probabilities show strong enhancement by selective adsorption resonances and overall changes in scattering intensities due to other aspects of the rotational degrees of freedom. Temperature-dependent HD-scattering probabilities show the effect of inelastic scattering on rotationally inelastic scattering and selective adsorption resonances.