Reduced density matrix approach for gas-solid scattering

A short time propagation algorithm for the reduced density matrix is derived which describes the interaction between a particle hitting a surface and the thermal vibrations of the lattice. The algorithm, including the dissipative terms, is derived directly from the full particle-bath density matrix and Hamiltonian. The model is used to examine the scattering of He, Ne and Ar from a model Cu surface over a wide range of energy and temperature. The method provides a good description of particle behavior for weak, intermediate and strong coupling cases.