Homonuclear diatomic scattering from solid surfaces: A hard cube model

A classical mechanical hard cube theory describing the scattering patterns of homonuclear diatomic gas beams scattered from well-defined solid surfaces is presented. The diatomic gas molecules are approximated by ellipses having rotational as well as translational energy. Scattering patterns are numerically computed with the assumption that only single collision processes are important. Analytical expressions for scattering patterns are derived by assuming that the ellipticity of a gas molecule is close to 1 and that the incident rotational energy is zero. The analytical scattering patterns exhibit the same qualitative features as the numerically computed patterns, though they do not agree quantitatively with them. The theory is briefly compared with previously presented hard cube models.