Dissertation / PhD Thesis/Book

PreJuSER-22714

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Heyd-Scuseria-Ernzerhof Screened-Exchange Hybrid Functional for Complex Materials: All-Electron Implementation and Application

Schlipf, M. (Corresponding author)FZJ*

2012
Forschungszentrum Jülich GmbH Zentralbibliothek, Verlag Jülich
ISBN: 978-3-89336-857-0

Please use a persistent id in citations: http://hdl.handle.net/2128/7578

Abstract: The design of suitable materials for application in future devices requires a detailed understanding of their electronic and structural properties. The $\textit{ab initio}$ method density functional theory (DFT) has emerged as the most commonly applied materials. The limits of the predictive power of DFT are set by the availability of precise approximations to the exchange-correlation functional. In ths thesis, we developed a scheme to realize screened nonlocal potentials within the full-potential linearized augmented-plane-wave (FLAPW) method and applied it, in particular, to the screened Heyd-Scuseria-Ernzerhof (HSE) functional. Incorporating a certain fraction of nonlocal exchange, hybrid functionals improve on the conventional local functions by partly correcting for the spurios self interaction. This self interaction is most prominent in materials with localized states, so that we expect an improved description of transition-metal and rare-earth compounds. The strong localization of the $\textit{d}$ and $\textit{f}$ electrons in these materials complicates a description by pseudopotential methods, so that they are particularly suited for the all-electron FLAPW scheme. The nonlocal exchange is computationally very demanding, hence, we discuss two apprximations to improve the computationally very demanding, hence, we discuss two approximations to improve the computation time of hybrid functional calculations: a spacial restriction of the nonlocal exchange and the employment of a smaller$\textit{k}$-point mesh in the calculation of the nonlocal exchange. We demonstrate that both schemes are feasible for selected materials, but not in general for all materials. [...]

Note: Record converted from VDB: 12.11.2012
Note: RWTH Aachen, Diss., 2012

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Contributing Institute(s):

1. Quanten-Theorie der Materialien (PGI-1)
2. Quanten-Theorie der Materialien (IAS-1)

Research Program(s):

1. Grundlagen für zukünftige Informationstechnologien (P42)

Appears in the scientific report 2012

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Database coverage:

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