Regensburg 2000 – scientific programme

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HL: Halbleiterphysik

HL 42: Elektronentheorie

HL 42.5: Talk

Friday, March 31, 2000, 11:30–11:45, H14

Exact exchange (EXX) and GW calculations of the bulk electronic structure of Si, Ge, BeSe, BeTe, MgSe and MgTe — •Andrzej Fleszar — Theoretische Physik I, Uni Würzburg, 97074 Würzburg

The Kohn-Sham exact exchange (plus LDA correlations) scheme has been applied in the case of Si, Ge and a series of large gap II-VI compounds. The resulting energy gaps between occupied and empty bands are much better in the EXX scheme as in the LDA and compare very well with experiment. The band widths, as well as the binding energies of occupied states, are about 0.2 - 0.3 eV smaller in the EXX scheme as compared to the LDA. A quasiparticle GW calculation based on the EXX Kohn-Sham wave functions and energies gives small self-energy corrections to the energy gaps and compares very well with both experiment and GW calculations based on the LDA band structure. For occupied band widths the quasiparticle calculation results in their further reduction.