Regensburg 2013 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 58: Poster Session III (Solid-liquid interfaces; Scanning probe and other methods; Electronic structure theory; Spin-orbit interaction)
O 58.74: Poster
Mittwoch, 13. März 2013, 18:15–21:45, Poster B1
HSE06 and G0W0 for Pyrite- and Marcasite-type compounds — •Timo Schena, Pengxiang Xu, Martin Schlipf, Gustav Bihlmayer, Markus Betzinger, Christoph Friedrich, and Stefan Blügel — Peter Grünberg Institut and Institute for Advanced Simulation, Forschungszentrum Jülich & JARA, D-52425 Jülich, Germany
The accuracy of density functional theory (DFT) depends only on the choice of a suitable approximation for the xc-functional. The local xc-functionals LDA and PBE can result in a severe underestimation of band gaps in insulators and semiconductors. The prediction of the band gap is usually improved considerably by employing hybrid functionals (e.g. HSE06) or many-body-perturbation-theory (e.g. G0W0). Recently, these methods have been implemented in the Jülich-all-electron DFT code FLEUR [1,2]. However, in this work we present material systems, for which no considerable improvement of the band gaps is obtained in comparison to the experimental values. In opposite sometimes even a worsening is found. Amongst others, we present a detailed analysis of the electronic structure of Pyrite-like compounds FeS2, RuS2, OsS2, NiP2 and Marcasite-type compounds FeS2, FeSe2, FeTe2 and CrCl2. By detecting similarities and differences, we can draw some hypotheses of what is causing the shortcomings of HSE06 and G0W0 for these systems. We gratefully acknowledge funding from BMBF of the NADNuM project 03SF0402A.
[1] www.judft.de, [2] C. Friedrich et al. JPCM 24 293201 (2012)