Kohn-Sham band gaps and potentials of solids from the optimised effective potential method within the random phase approximation

Autor(en)

Jiri Klimes, Georg Kresse

Abstrakt

We present an implementation of the optimised effective potential (OEP) scheme for the exact-exchange (EXX) and random phase approximation (RPA) energy functionals and apply these methods to a range of bulk materials. We calculate the Kohn-Sham (KS) potentials and the corresponding band gaps and compare them to the potentials obtained by standard local density approximation (LDA) calculations. The KS gaps increase upon going from the LDA to the OEP in the RPA and finally to the OEP for EXX. This can be explained by the different depth of the potentials in the bonding and interstitial regions. To obtain the true quasi-particle gaps the derivative discontinuities or G ₀ W ₀ corrections need to be added to the RPA-OEP KS gaps. The predicted G ₀ W ₀@RPA-OEP quasi-particle gaps are about 5% too large compared to the experimental values. However, compared to G ₀ W ₀ calculations based on local or semi-local functionals, where the errors vary between different materials, we obtain a rather consistent description among all the materials.

Organisation(en)

Computergestützte Materialphysik

Journal

Journal of Chemical Physics

Band

140

Anzahl der Seiten

13

ISSN

0021-9606

DOI

https://doi.org/10.1063/1.4863502

Publikationsdatum

02-2014

Peer-reviewed

Ja

ÖFOS 2012

103009 Festkörperphysik, 103015 Kondensierte Materie, 103025 Quantenmechanik, 103036 Theoretische Physik

Schlagwörter

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/a76a2dd6-3469-4717-b6a6-ef6418d5ae8d