Ab initio adiabatic He and Ne interaction on Ag: An all-electron calculation

We report an ab initio calculation of the adiabatic electronic properties of He and Ne atoms interacting with an Ag-like jellium metal surface, using the embedding method and the density functional theory in the local density approximation (LDA). Differently from previous results obtained in this framework, the noble atoms are described with their full potential. The linearized augmented plane-wave basis set is introduced to tackle the Kohn-Sham equation. Attention is focused on the atom-surface potential in the repulsive regime, i.e., at distances from the jellium edge smaller then the adsorption one, where the LDA has been shown to work well, and which are relevant in elastic and inelastic scattering experiments of He and Ne on metals. For incident atoms with initial kinetic energies in the experimental range of interest, it is shown that Ne gets closer to the metal than He as previously found with an Al substrate. An analysis of the shift of the atomic core levels by varying the atom-metal distance is also presented. [S0163-1829(98)01539-2].