UPS of xenon atoms adsorbed on metal surfaces

This paper discusses assignments and ionization energy shifts of UPS of xenon atoms adsorbed on metal surfaces. It is suggested that the ordering in split energy levels, which has been controversial in previous publications, may be explained as a function of Xe coverages. It has been shown that the ionization energy shift is due to the final effects. The donimant effect may be a valence force between an adsorbate ion and surrounding Xe atoms.