Trajectory Studies of Hyperthermal Xe Scattering from GaAs (110)

We present the results of stochastic classical trajectory simulations of the scattering of a non-reactive gas, xenon, from a semiconductor surface of known structure and electronic and vibrational properties, GaAs (110). The range of incident energies considered is 1 to 8 eV, in order to make direct comparison with results of molecular beam experiments reported in the accompanying paper. We employed a 48-atom 3-layer slab of GaAs, with periodic boundary conditions in two dimensions and frictional and stochasitic forces in the third (surface normal) dimension. Pairwise additive Lennard-Jones potentials describe the gas- surface interaction. The calculations reproduce the large energy exchange and surprising structural sensitivity observed experimentally.