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 ${\mathrm{O}}_2$ at normal energies below 1 eV. The amount of surface corrugation strongly depends on the kind of incident particle (Ar, CO, ${\mathrm{O}}_2$).

• Received 19 October 1988

DOI:https://doi.org/10.1103/PhysRevB.39.3915