Reversible relaxation at charged metal surfaces: An ab initio study

Results of an ab initio density functional theory study of atomic and electronic relaxation at electrically charged surfaces of Au suggest that the outward relaxation of the top layer at negative excess charge is driven by electrostatic forces on the surface atoms due to the incomplete screening of the external electric field. The relaxation amplitude agrees well with experiments on Au (111) in electrolyte. Electron redistribution between bonding and antibonding states in the plane containing the surface atoms may contribute to the charge response of the surface stress.