BOUND-STATE SPECTROSCOPY OF HE ADSORBED ON NACL(001) - BAND-STRUCTUREEFFECTS

The interaction between atoms and surfaces may be probed by bound stat e resonance spectroscopy. The experiments are usually interpreted with in the free particle picture which assumes that the energy-momentum re lation of atoms adsorbed onto a surface is described by 2D parabolic b ands. We calculate and analyze the band structure of an atom adsorbed on a model corrugated surface and follow its behavior as the interacti on potential evolves from weakly to strongly corrugated. Besides the e xpected reduction of degeneracy and development of gaps, we obtained a sizable correction to the bound state energies. We employ our results to reanalyze the available experiments on the system He-NaCl(001).