Onset of surface corrugation in molecular scattering from Ag(111)

Although close-packed metal surfaces are commonly assumed to be flat for beam energies up to about 1 eV, we find that the close-packed Ag(111) surface is considerably corrugated for O₂ at normal energies below 1 eV. The amount of surface corrugation strongly depends on the kind of incident particle (Ar, CO, O₂).