ANTICORRUGATION IN INELASTIC HE-ATOM SCATTERING FROM RH(111) SURFACES

Recent measurements supported by nb initio calculations have shown tha t the interaction of He atoms with transition metal surfaces is antico rrugating, i.e., the electron density seen by He is higher in the brid ge positions than in the on-top positions. By shifting the electron ch arge density away from the atomic positions and using the Esbjerg-Nors kov approach to determine the interaction potential, we evaluate the i nelastic reflection coefficients of He with Rh(lll). The structure fac tor introduced by the anticorrugation explains, in a simple way, the h igh intensity observed for the resonant mode.