Quasiparticle Self-Consistent GW Theory.pdf

a r X i v : c o n d - m a t / 0 5 1 0 4 0 8 v 2 [ c o n d - m a t .m t r l - s c i ] 2 0 M a r 2 0 0 6 Quasiparticle Self-Consistent GW Theory M. van Schilfgaarde,1 Takao Kotani,1 and S. Faleev2 1Arizona State University, Tempe, AZ, 85287 2Sandia National Laboratories, Livermore, CA 94551 Abstract In past decades the scientific community has been looking for a reliable first-principles method to predict the electronic structure of solids with high accuracy. Here we present an approach which we call the quasiparticle self-consistent GW approximation (QPscGW ). It is based on a kind of self-consistent perturbation theory, where the self-consistency is constructed to minimize the per- turbation. We apply it to selections from different classes of materials, including alkali metals, semiconductors, wide band gap insulators, transition metals, transition metal oxides, magnetic insulators, and rare earth compounds. Apart some mild exceptions, the properties are very well described, particularly in weakly correlated cases. Self-consistency dramatically improves agree- ment with experiment, and is sometimes essential. Discrepancies with experiment are systematic, and can be explained in terms of approximations made. 1 The Schro?dinger equation is the fundamental equation of condensed matter, and the im- portance of being able to solve it reliably can hardly be overestimated. The most widely used theory in solids, and now in quantum chemistry, is the celebrated local density approx- imation (LDA)[1]. In spite of its successes, it is well known that the LDA suffers from many deficiencies, even in weakly correlated materials (see Figs. 1 and 2). This has stimulated the development of flavors of extensions to the LDA to redress one or another of its failures, such as the LDA+U method. Each of these methods improves one failing or another in the LDA, but they often bear a semi-empirical character, and none can be considered universal and parameter-free. Thus we are far f