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arXiv · 1710.03722

First-Principles Supercell Calculations of Small Polarons with Proper Account for Long-Range Polarization Effects

Sebastian Kokott·Sergey V Levchenko·Patrick Rinke·Matthias Scheffler
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Abstract

We present a density functional theory (DFT) based supercell approach for modeling small polarons with proper account for the long-range elastic response of the material. Our analysis of the supercell dependence of the polaron properties (e.g., atomic structure, binding energy, and the polaron level) reveals long-range electrostatic effects and the electron-phonon interaction as the two main contributors. We develop a correction scheme for DFT polaron calculations that significantly reduces the dependence of polaron properties on the DFT exchange-correlation functional and the size of the supercell in the limit of strong electron-phonon coupling. Using our correction approach, we present accurate all-electron full-potential DFT results for small polarons in rocksalt MgO and rutile TiO$_2$.

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Sebastian Kokott, Sergey V Levchenko, Patrick Rinke, Matthias Scheffler. 2017-10-10. First-Principles Supercell Calculations of Small Polarons with Proper Account for Long-Range Polarization Effects. https://doi.org/10.1088/1367-2630%2Faaaf44

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