SELF-INTERACTION CORRECTIONS IN SEMICONDUCTORS

We propose a scheme to generate pseudopotentials from strictly self-co nsistent self-interaction-corrected local-density-approximation (SIC-L DA) calculations, that are firmly rooted within density functional the ory, and use them in a standard LDA calculation of the structural prop erties and the eigenvalue spectrum in crystalline Si, Ge, Sn, and GaAs . Thus we avoid the serious shortcomings of LDA in small atoms and nev ertheless use consistently the same method in both atoms and solids, s ince LDA and SIC-LDA coincide for the completely delocalized valence e lectrons of these materials. We show that significant effects arise fr om an improved description of the core. In particular, Ge, which appea rs to be a metal with band overlap at the Gamma point of the Brillouin zone in LDA, can be correctly described as an indirect-gap semiconduc tor. Still, it is argued that fully self-consistent self-interaction c orrections can only eliminate a small part of the gap problem in sp-bo nded semiconductors.