Electronic structure calculations of thin films of RbF

Electronic structure of thin films of rubidium fluoride is investigated wit hin a next-nearest-neighbour approximation of the LCAO approach, with overl ap integrals included. For the bulk structure calculations, semi-empirical parameters are fitted in order to reproduce the experimental band gap width , electron affinity and ionicity of RbF. For the thin-film structure calcul ations, one center parameters are corrected to take into account the Madelu ng potential differences in the subsequent atomic layers of a considered sl ab. For very thin films (two lattice constants or less), a strong dependenc e of the valence band width as well as the layer-density-of-states distribu tions on the slab thickness is found. The surface electronic structure of R bF is examined and it is shown-in accordance with previous estimations-that no surface states exist at the (001) surface. (C) 1999 Elsevier Science B. V. All rights reserved.