Publication date: Feb 22, 2022
This work details how to determine structural prototypes for the cubic perovskite structure that are used to study the B-site displacements in the cubic, paraelectric phase. Car-Parrinello MD simulations of cubic barium titanate (BaTiO3) show the titanium displacements from the undistorted cubic structure. Using a systematic symmetry analysis we construct microscopic templates, i.e. representative structural models in the form of supercells that satisfy a desired point symmetry but are built from the combination of lower-symmetry primitive cells. Density functional theory calculations, using the microscopic templates as starting structures for a relaxation, are carried out to find structural prototypes of BaTiO3 with local polar distortions but with cubic point symmetry. The stability of these structures is studied as a function of volume and with respect to the zone-boundary phonons of pristine cubic BaTiO3. The stable distortions patterns for BaTiO3 are investigated for other titanates and for a handful of niobates and zirconates.
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File name | Size | Description |
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README.txt
MD5md5:9ccb1773bcd0affc0d3da6f9c99b5b4c
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1.2 KiB | Description of 'Figures_main', 'Figures_SI', 'prototypes', 'materials_displacements', 'materials_5atom_phonon' and 'pseudopotenials' |
Figures_main.zip
MD5md5:f9b290c5bbd5a2da62f439b47d66a822
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315.7 MiB | Contains directories with a brief README and the data to reproduce the figures in the main text, or directions to the relevant directory |
Figures_SI.zip
MD5md5:8c40506212060cf440794235f5f1d591
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243.0 MiB | Contains directories with a brief README and the data to reproduce the figures in the supplemental, or directions to the relevant directory |
prototypes.zip
MD5md5:81c8be20fe7fdacd1596c01a77e2a25f
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246.9 KiB | Contains the two prototypes of paraelectric BaTiO3 and a cif for a representation of each of the 27 distinct cubic microscopic templates of spacegroup 221 with occupied Wyckoff positions: 1a, 1b, 3c. In this representation BaTiO3 is used where Ba occupies the 1a, Ti the 1b, and O the 3c Wyckoff position in the high-symmetry phase. |
materials_displacements.zip
MD5md5:de1207ab0f532282f4733e8d039ad45d
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18.2 MiB | This directory contains the output of the pw.x relax calculations of the 4+4 and 2+6 displacement patterns with fixed lattice parameters. |
materials_5atom_phonons.zip
MD5md5:785730b6237f72e7297577ad43498877
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8.4 MiB | This directory contains the phonon calculations for the 5 atom cubic structures |
pseudopotentials.zip
MD5md5:ff653596767e303f7f23ba228810a2c7
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27.2 MiB | contains the pseudopotentials used in the calculations |
2022.32 (version v2) [This version] | Feb 22, 2022 | DOI10.24435/materialscloud:jc-ky |
2021.104 (version v1) | Jul 12, 2021 | DOI10.24435/materialscloud:pg-50 |