The authors study the electronic structure of the epitaxially grown Pd monolayer on the Ta(011) surface as well as the electronic properties of other related systems (Pt overlayer; Nb, Mo and W substrate). To this end an s-d electronic tight-binding Hamiltonian is treated using the recursion method technique. The calculations confirm that the 'noble-metal' properties of the overlayer are mainly due to the overlayer-substrate electron hybridization in which the role of s electrons is not negligible. The possible contribution of initial-stage effects to core-level shifts is also considered. For Pd adatoms they obtain a semi-quantitative agreement with experiment.

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Semiempirical tight-binding self-consistent calculations were performed for transition-metal alloy nonpolar surfaces: MTi(011) and M3 Ti(111) (M =Ni, Pd, Pt). For both kinds of surfaces we find two occupied surface-state bands which appear due to the surface-potential shift and should be accompanied by a negative surface core-level shift for the M atoms. For the Ti atoms we find a surface state at the Fermi energy for M3Ti(111) faces without any need for the surface-potential change. For MTi(011) an analogous surface feature is not well separated from the bulk states.

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