Regensburg 2016 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 43: Oxides and Insulators: Adsorption I

O 43.4: Vortrag

Dienstag, 8. März 2016, 14:45–15:00, H6

Derivation and Validation of a Classical Potential for Surfaces of Ionic Crystals — •Sara Panahian Jand and Payam Kaghazchi — Physikalische und Theoretische Chemie, Freie Universität Berlin, Takustr. 3, 14195 Berlin, Germany

In this work, we present a method to parametrize Coulomb+Buckingham (C-B) pairwise potentials that can be used to study the atomic structure and stability of surfaces of ionic crystals. Our training sets are based on density functional theory (DFT) calculations. In the parametrization procedure, ionic charges are calculated using electrostatic energies and then Buckingham parameters are fitted to reproduce energy changes versus atomic displacements and unit cell size in bulk. Although depending on the starting points different sets of parameters are obtained, only one set of them can qualitatively reproduce (DFT-calculated) atomic structure and stability of low-index surfaces of ionic crystals. We found that the constructed potentials can calculate relaxations and relative stabilities of higher-index surfaces in good agreement with experiments and DFT [1]. Most of electrode and (solid) electrolyte materials in Li-based batteries have ionic crystals. Therefore, the method discussed in the present work [2] can be applied to construct reliable classical potentials for these materials to study electrode/electrolyte interfaces in Li-based batteries.

[1] S. Panahian Jand and P. Kaghazchi, J. Phys.: Condens. Matter, 26, 262001 (2014)

[2] S. Panahian Jand and P. Kaghazchi, submitted