Berlin 2015 – scientific programme
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TT: Fachverband Tiefe Temperaturen
TT 79: Frontiers of Electronic Structure Theory: Optical Excitation (organized by O)
TT 79.4: Talk
Wednesday, March 18, 2015, 16:00–16:15, MA 004
A hybrid QM/EMT approach to charge state corrections — •Osman Baris Malcioglu1 and Michel Bockstedte2 — 1Lst.f.Theor.Festkörperphysik, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91058 Erlangen, Germany — 2FB Materialwissenschaften & Physik Universität Salzburg, 5020 Salzburg, Austria
Localized charge at surfaces, interfaces, or in volume
materials naturally occur due to the ionization of adsorbates or
defects. A robust quantitative description of charged systems is
a prerequisite to explore the physics of adsorbates, surface and bulk
defects of materials such as metal oxides. The popular supercell
approach requires charge neutrality per supercell. For
charged systems this is enforced by compensation charges. The resulting
spurious interaction can be corrected a-posteriori [1,2]. Recently, a
scheme based on model fitting the localized charge and dielectric
screening was proposed [1]. Here, we present a fully automated and
efficient hybrid QM/EMT approach for handling long-reach fields. The
response of the medium and the localized charge density of the
ab-initio calculations are represented by a finite element function
space. The relevant physical observables are obtained using an
auto-adaptive mesh solver. We demonstrate applications of our
approach to charge state corrections of surface and bulk defects slabs
in comparison with the earlier approaches [1,2].
1 H.-P. Komsa
and A. Pasquarello, Phys. Rev. Lett. 110, 095505
(2013).
2 C. Freysoldt, J. Neugebauer, and C. G. Van de Walle,
Phys. Rev. Lett. 102, 016402 (2009).