Berlin 2015 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 85: Frontiers of Electronic Structure Theory: Many-Body Effects on the Nano-Scale VI
O 85.8: Vortrag
Donnerstag, 19. März 2015, 17:00–17:15, MA 004
Improved Ground State Electronic Structure and Optical Dielectric Constants With a Semi-Local Exchange Functional — •Vojtěch Vlček1, Gerd Steinle-Neumann1, Linn Leppert1, Rickard Armiento2, and Stephan Kümmel1 — 1University of Bayreuth, Germany — 2Linköping University, Sweden
For a set of solids, we explore a recently developed generalized gradient exchange functional (AK13) that has two characteristic features: its enhancement factor diverges for large reduced density gradients s as sln(s) and its potential changes discontinuously at integer electron numbers. We apply the functional to semiconductors, Mott insulators, and ionic crystals and compare results for band structure and dielectric constants with a standard GGA. The AK13 functional provides a better description of the KS orbitals and we observe a qualitative improvement both in the bandgaps and in the optical dielectric constants, especially for the small gap semiconductors we explore (Ge, α-Sn, and CdO)