HD scattering from Pt(111): rotational excitation probabilities

We measured the rotationally inelastic diffractive scattering probabilities for an HD beam colliding with a smooth Pt(111) surface. These large T → R inelastic probabilities were measured as a function of incidence angle for a 110 meV beam energy. The results are in excellent agreement with a simple physical model of an eccentrically weighted sphere colliding with a hard wall, with an attractive well depth of 55±10 meV. The numerical ‘‘GR’’ method of Garcia and co-workers was found superior to an eikonal method in solving this rotational quantum boundary value problem.