Electron states of ultrathin Pd and Cu films on (001) Ag.

We present the results of a theoretical calculation of the electronic structure of a monolayer of Pd and Cu deposited on the (001) surface of Ag. The adsorbate atoms are placed in a central site with the same lateral periodicity as a parallel plane of the substrate. The method of calculation is a parametrized LCAO with hopping integrals determined through a fit to bulk data.Charge transfer effects are taken approximately into account by assuming the intraatomic parameters to vary as the valence orbital ionization potentials. Energy bands and local densitiesof states are given and the nature and location of the adsorbate states are discussed. The results are compared with the experimental data: good agreement is found for the Pd on Ag system.For Cu on Ag we find that our assumptions do not explain the photoemission data and suggest that some clustering of Cu atoms occurs during the deposition.