Quasiparticle band structure based on a generalized Kohn-Sham scheme

Autor(en)

F Fuchs, J Furthmüller, F Bechstedt, M Shishkin, Georg Kresse

Abstrakt

We present a comparative full-potential study of generalized Kohn-Sham (gKS) schemes with explicit focus on their suitability as starting point for the solution of the quasiparticle equation. We compare G0 W0 quasiparticle band structures calculated upon local-density approximation (LDA), screened-exchange, HSE03, PBE0, and Hartree-Fock functionals for exchange and correlation (XC) for Si, InN, and ZnO. Furthermore, the HSE03 functional is studied and compared to the generalized gradient approximation (GGA) for 15 nonmetallic materials for its use as a starting point in the calculation of quasiparticle excitation energies. For this case, the effects of self-consistency in the GW self-energy are also analyzed. It is shown that the use of a gKS scheme as a starting point for a perturbative quasiparticle correction can improve upon the deficiencies found for LDA or GGA starting points for compounds with shallow d bands. For these solids, the order of the valence and conduction bands is often inverted using local or semilocal approximations for XC, which makes perturbative G0 W0 calculations unreliable. The use of a gKS starting point allows for the calculation of fairly accurate band gaps even in these difficult cases, and generally single-shot G0 W0 calculations following calculations using the HSE03 functional are very close to experiment. © 2007 The American Physical Society.

Organisation(en)

Computergestützte Materialphysik

Externe Organisation(en)

Friedrich-Schiller-Universität Jena, Universität Wien

Journal

Physical Review B

Band

76

Anzahl der Seiten

8

ISSN

1098-0121

DOI

https://doi.org/10.1103/PhysRevB.76.115109

Publikationsdatum

2007

Peer-reviewed

Ja

ÖFOS 2012

1030 Physik, Astronomie

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/3ab878ac-0cda-4e89-9fbe-6b5160bf0990