EFFICIENT QUASI-PARTICLE BAND-STRUCTURE CALCULATIONS FOR CUBIC AND NONCUBIC CRYSTALS

An efficient method developed for the calculation of quasiparticle corrections to density-functional-theory-local-density-approximation (DFT-LDA) band structures of diamond and zinc-blende materials is generalized for crystals with other cubic, hexagonal, tetragonal, and orthorhombic Bravais lattices. Local-field effects are considered in the framework of a LDA-like approximation. The dynamical screening is treated by expanding the self-energy linearly in energy. The anisotropy of the inverse dielectric matrix is taken into account. The singularity of the Coulomb potential in the screened-exchange part of the electronic self-energy is treated using auxiliary functions of the appropriate symmetry. An application to the electronic quasiparticle band structure of wurtzite 2H-SiC is presented within the approach of norm-conserving, nonlocal, fully separable pseudopotentials and a plane-wave expansion of the wave functions for the underlying DFT-LDA. © 1995 The American Physical Society.