Surface densities of states for normal photoemission from Mo(110) and W(111)

Tight-binding calculations of one-dimensional densities of states on Mo(110) and W(111) are presented. As reported earlier for W(001), hybridization gaps contain localized surface states or resonances, and band-edge singularities are modified near the surface. Prominent structures in directional photoemission spectra are discussed in the light of our results, and further experiments using polarized light are suggested to test our assignments.