Dresden 2009 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 41: Ab-initio approaches to excitations in condensed matter I
O 41.4: Vortrag
Mittwoch, 25. März 2009, 15:45–16:00, SCH 251
Implementation of the exact-exchange Kohn-Sham functional within the all-electron FLAPW method — •Markus Betzinger1, Christoph Friedrich1, Stefan Blügel1, and Andreas Görling2 — 1Institut für Festkörperforschung and Institute for Advanced Simulation, Forschungszentrum Jülich, 52425 Jülich, Germany — 2Lehrstuhl für Theoretische Chemie, Universität Erlangen-Nürnberg, Egerlandstr. 3, 91058 Erlangen, Germany
The success of density-functional theory (DFT) relies on the availability of accurate approximations for the exchange-correlation (xc) functional. Standard xc functionals, such as the local-density and the generalized-gradient approximation, suffer from several shortcomings: an unphysical electronic self-interaction, no discontinuity of the xc potential at integral particle numbers, wrong asymptotic behavior etc. Orbital-dependent functionals are a promising new generation of xc functionals. The simplest variant consistent with the Kohn-Sham theory requiring a local xc-potential is the exact-exchange (EXX) functional. It does not exhibit the above mentioned deficiencies. We implemented the EXX functional within the full-potential augmented-planewave (FLAPW) method using a specifically designed auxiliary basis set for the optimized effective potential (OEP) equation. We demonstrate that the auxiliary and FLAPW basis must be properly balanced to avoid spurious oscillations in the exact exchange potential and show first results for prototype semiconductors and insulators.