Investigation of density functionals to predict both ground-state properties and band structures

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Abstract
By incorporating part of the correlation energy into a modified kinetic energy functional within a Kohn-Sham-like theory, it is possible to obtain significantly altered band structures, while preserving good agreement with experiment for ground state properties well described by the usual local density approximation (LDA). A particular such functional obtained by introducing a local density-dependent mass is investigated. By construction, it reproduces the valence-band narrowing of free-electron-like metals. Applied to semiconductors, a significant gap increase with respect to the LDA gap is observed in silicon and germanium; for diamond carbon, the correction is negligible. The proposed strategy is quite general and could facilitate the construction of density functionals which simultaneously predict ground state properties and band structures for a given class of materials. © 1996 The American Physical Society.