TY  - JOUR
AU  - Freimuth, Frank
AU  - Blügel, Stefan
AU  - Mokrousov, Yuriy
TI  - Band gaps of insulators from moment-functional-based spectral density functional theory
JO  - Physical review / B
VL  - 108
IS  - 16
SN  - 2469-9950
CY  - Woodbury, NY
PB  - Inst.
M1  - FZJ-2024-02839
SP  - 165137
PY  - 2023
AB  - Within the method of spectral moments it is possible to construct the spectral function of a many-electron system from the first 2P spectral moments (P=1,2,3,⋯). The case P=1 corresponds to standard Kohn-Sham density functional theory (KS-DFT). Taking P>1 allows us to consider additional important properties of the uniform electron gas (UEG) in the construction of suitable moment potentials for moment-functional-based spectral density functional theory (MFbSDFT). For example, the quasiparticle renormalization factor Z, which is not explicitly considered in KS-DFT, can be included easily. In the four-pole approximation of the spectral function of the UEG (corresponding to P=4) we can reproduce the momentum distribution, the second spectral moment, and the charge response acceptably well, while a treatment of the UEG by KS-DFT reproduces from these properties only the charge response. For weakly and moderately correlated systems we can reproduce the most important aspects of the four-pole approximation by an optimized two-pole model, which leaves out the low-energy satellite band. From the optimized two-pole model we extract parameter-free universal moment potentials for MFbSDFT, which improve the description of the band gaps in Si, SiC, BN, MgO, CaO, and ZnO significantly.
LB  - PUB:(DE-HGF)16
DO  - DOI:10.1103/PhysRevB.108.165137
UR  - https://juser.fz-juelich.de/record/1025376
ER  -