Energy Transfer in Molecular Gas-Surface Interactions

A theoretical study of energy accommodation, momentum accommodation and reduced force coefficients for the diatomic molecular gases O$_2$, N$_2$ and H$_2$ scattering from Au, Al and SiO$_2$ surfaces has been carried out. The theory is a mixed classical-quantum formalism which includes energy transfer between the surface and molecule through translational motion and internal molecular rotational and vibrational excitations. The translational and rotational degrees of freedom are treated classically while the molecular internal vibrational excitation is treated quantum mechanically with a semiclassical formalism. The accommodation coefficients and force constants are calculated as functions of the surface temperature, incident beam angle, incident energy, and mass ratio of the incident molecule to the surface substrate atomic mass. The calculations are calculated with recent experimental data and show good agreement in general.