Molecular dynamics study of gas-surface interaction (construction of a gas-surface scattering model)

The Multistage model for diatomic molecules scattering from a solid surface is presented, which is based on a large body of data obtained from molecular dynamics simulations and molecular beam experiments. The molecular dynamics method is used for the numerical analysis of the scattering of an oxygen gas molecule from a clean graphite surface. The angular and velocity distributions agree well with experimental results, which were shown in our previous report. The scattering direction, translational energy and rotational energy of the gas molecule after each collision are saved as the data base. The basic idea of the model is to separate the collision into different stages. At each stage, the energy loss, the scattering direction and the trapping probability of the gas molecule are determined. The angular and velocity distribution of the model agrees with those of molecular beam experiments.