Tangential momentum and thermal accommodation coefficients for hydrogen molecules on graphite surface

The scattering of hydrogen molecules from graphite surface was studied through molecular dynamics simulation. The trajectories of the hydrogen molecules and surface atoms were calculated. The distributions of velocity and energy after reflection were obtained depending on direction and quantity of the initial velocity. The energy and tangential momentum accommodation coefficients were calculated for cases where incident velocity distribution can be approximated by Maxwellian function and mean velocity is negligible. Obtained coefficients are in satisfactory agreement with experimental data.