Polarons in semilocal density functional theory: localization, many-body self-interaction, and formation energy
ORAL
Abstract
We develop a semilocal functional for overcoming the self-interaction of electron and hole polarons by enforcing the piece-wise linearity upon electron occupation. We obtain localized polarons with structural and electronic properties in agreement with references from a hybrid functional satisfying the same constraint. We then develop a scheme accounting for the effects of Fock exchange, further improving the formation energies. We demonstrate that the difference between the one-body and the many-body self-interaction is related to screening effects. Case studies include the electron polaron in BiVO4, the hole polaron in MgO, and the hole trapped at the Al impurity in α-SiO2.
*This work has been realized in relation to the National Center of Competence in Research (NCCR) ``Materials' Revolution: Computational Design and Discovery of Novel Materials (MARVEL)'' of the SNSF. The calculations have been performed at the Swiss National Supercomputing Centre (CSCS) (grant under projects ID s879 and mr25) and at SCITAS-EPFL.
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Publication: "Polarons in semilocal density functional theory: localization, many-body self-interaction, and formation energy", S. Falletta and A. Pasquarello, (in preparation)
Presenters
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Stefano Falletta
- Chaire de Simulation à l'Echelle Atomique (CSEA), Ecole Polytechnique Fédérale de Lausanne (EPFL)