GW approximation with LSDA+U method and applications to NiO, MnO, and V2O3

作     者：S. Kobayashi Y. Nohara S. Yamamoto T. Fujiwara 

作者机构：Department of Applied Physics The University of Tokyo Tokyo 113-8656 Japan Core Research for Evolutional Science and Technology–Japan Science and Technology Agency (CREST-JST) Kawaguchi 332–0012 Japan Center for Research and Development of Higher Education The University of Tokyo Tokyo 113-0033 Japan 

出 版 物：《Physical Review B》 (物理学评论B辑：凝聚态物质与材料物理学)

年 卷 期：2008年第78卷第15期

页      面：155112-155112页

核心收录：

学科分类：07[理学] 0702[理学-物理学] 

基　　金：Ministry of Education  Culture  Sports  Science  and Technology of Japan 

摘      要：A GW approximation (GWA) method named U+GWA is proposed, where we can start GWA with more localized wave functions obtained by the local spin-density approximation (LSDA)+U method. Then GWA and U+GWA are applied to MnO, NiO, and V2O3 in antiferromagnetic phase. The band gaps and energy spectra show excellent agreement with the experimentally observed results and are discussed in detail. The calculated width of d bands of V2O3 is much narrower than that of the observed one which may be a mixture of t2g2 multiplet and single-electron t2g level. GWA or U+GWA does not work also in the paramagnetic phase of V2O3 and the reason for this is clarified. The method of the unique choice of on-site Coulomb interaction is discussed in detail. The criterion for whether we should adopt GWA or U+GWA is discussed and is assessed with the help of the off-diagonal elements of the self-energy.