The surface electronic structure of epitaxial (√3 x √3)R30° ErSi1.7 layers on Si(111) was studied by high-resolution angle-resolved ultra-violet photo-emission spectroscopy. Typical surface states or resonances were unambiguously identified and their band dispersions mapped along high symmetries of the (1 x 1) surface Brillouin zone. These data were compared to the band structure of two-dimensional p(1 x 1) Er silicide extensively studied in previous works. It was found that the prominent surface bands observed in the 0 to 3eV binding-energy range could be readily derived from the p(1 x 1) surface-silicide bands folded back into the reduced √3 x √3 zone. This indicated that the bulk silicide was also terminated with a buckled Si layer without vacancies, quite similar to the surface-silicide termination. In particular, specific surface bands reflect the doubly (essentially) occupied dangling bonds and the back bonds of the buckled Si top layer. Surface States and Reconstruction of Epitaxial √3 x √3 R30° Er Silicide on Si(111). P.Wetzel, S.Saintenoy, C.Pirri, D.Bolmont, G.Gewinner: Physical Review B, 1994, 50, 10886-92