POLARIZATION OF A METAL-SURFACE BY AN EXTERNAL PROTON

Density-functional formalism and the self-consistent Green functions m ethod have been applied to study the interaction of a proton with a je llium surface. Contrary to previous methods of a similar type, this ap proach allows one to treat accurately the extended screening charge di stribution in the metal for larger distances of the proton from the su rface. A detailed discussion is given of the density of screening char ge, the energetic position of bound states, and the binding energy of a proton and their dependence on the distance from the surface. It is found that the proton penetrates the jellium of r(s)=3 and is not adso rbed at the surface but absorbed. At small distances of the proton fro m the surface the screening charge density is relatively well localize d. [S0163-1829(98)02427-8].