Regensburg 2010 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 46: Density functional theory and beyond for real materials I

O 46.9: Vortrag

Mittwoch, 24. März 2010, 12:30–12:45, H34

Time-dependent Kohn-Sham self-interaction correction — •Dirk Hofmann, Thomas Körzdörfer, and Stephan Kümmel — Department of Physics, University of Bayreuth, 95440 Bayreuth

The self-interaction error of commonly used density functionals leads to a number of well-known problems in density functional theory (DFT). A particularly pronounced and practically important one is the serious overestimation of charge transfer in extended molecular systems.

Perdew and Zunger proposed an energy functional to overcome the selfinteraction problem (SIC), but their approach is not unitarily invariant and thus difficult to straightforwardly incorporate into Kohn-Sham theory. It has recently been shown, though, that the unitary invariance problem can systmatically be overcome by employing the generalized optimized effective potential (GOEP) formalism. However, in a time-dependent Kohn-Sham framework self-interaction correction is even more involved. The time-dependent optimized effective potential (TDOEP) equation is very demanding to solve and approximations to the TDOEP are not necessarily reliable.

Here, we extended the GOEP approach to the time-dependent case for a proper treatment of the unitary invariance problem. Furthermore, we implemented and tested this time-dependent Kohn-Sham SIC (TDSIC) scheme in a real-time Kohn-Sham propagation code. First results indicate that orbital localization improves the stability of the TDSIC scheme, making it a possible candidate for dealing with the problem of charge-transfer excitations.