Density functional application to strongly correlated electron systems

Abstract

The LSDA+U approach to density functional theory is carefully reanalyzed. Its possible link to single-particle Green's function theory is occasionally discussed. A simple and elegant derivation of the important sum rules for the on-site interaction matrix elements linking them to the values of U and J is presented. All necessary expressions for an implementation of LSDA+U into a non-orthogonal basis solver for the Kohn-Sham equations are given, and implementation into the FPLO solver [15] is made. Results of application to several planar cuprate structures are reported in detail and conclusions on the interpretation of the physics of the electronic structure of the cuprates are drawn.2

Subspace Representations in Ab Initio Methods for Strongly Correlated Systems

“…In contrast to the previously proposed "full" 13 , "on-site" 14 and "dual" 8 representations, our "tensorial" definition preserves the important property of tensorial invariance in the total occupancy of each subspace, the total energy and the ionic forces, by construction. The required expressions for the tensorially-invariant DFT+U energy functional and the resulting potential and ionic forces, have been presented.…”

Evidence of a field-induced Berezinskii–Kosterlitz–Thouless scenario in a two-dimensional spin–dimer system

“…Our total energy calculations were performed with the Full Potential Local Orbital code 50 within the LSDA þ U scheme 51 . We considered supercells of TK91 of various sizes with different Cu-spin configurations.…”

Electronic Structure and Optical Properties of Ce1-xLaxPtIn (0<x<1) Compounds by SPR-KKR-CPA and FPLO-CPA Methods

“…The band structure of LaPtIn and CePtIn is calculated by using of FPLO-CPA [11][12][13][14][15] and SPR-KKR-CPA [16,17] methods. We have performed the selfconsistent band calculations in local density approximation (LDA) within the generalized gradient approximations (GGA) for scalar-and full-relativistic mode.…”

“…The theoretical photoemission spectra and optical properties of LaPtIn and CePtIn are calculated by means of FPLO [11][12][13][14][15] and SPR-KKR [16,17] methods. The effect of chemical disorder on the electronic structure of Ce 1−x La x PtIn alloys is studied by the coherent potential approximation implemented in FPLO-CPA [13] and SPR-KKR-CPA [16,17] methods.…”