Han-Pu Liang^1*, Chuan-Nan Li^2*, Ran Zhou³, Xun Xu¹, Xie Zhang⁴, Jingxiu Yang⁵, Su-Huai Wei¹

1 Beijing Computational Science Research Center, Beijing, 100193, China

2 Department of Physics, University of Science and Technology of China, Hefei 230026, China

3 Department of Physics, Beihang University, Beijing 100191, China

4 School of Materials Science and Engineering, Northwestern Polytechnical University, Xi’an, 710072, China

5 Key Laboratory for Comprehensive Energy Saving of Cold Regions Architecture of Ministry of Education, School of Materials Science and Engineering, Jilin Jianzhu University, Changchun, China

* Corresponding authors emails: hanpuliang@csrc.ac.cn, lcn1996@mail.ustc.edu.cn

DOI10.24435/materialscloud:k5-qx [version v1]

Publication date: Apr 24, 2024

How to cite this record

Han-Pu Liang, Chuan-Nan Li, Ran Zhou, Xun Xu, Xie Zhang, Jingxiu Yang, Su-Huai Wei, Dataset of disorder-stabilized unfavorable coordination in complex ABX₂ compounds, Materials Cloud Archive 2024.63 (2024), https://doi.org/10.24435/materialscloud:k5-qx

Description

The crystal structure of a material is essentially determined by the nature of its chemical bonding. Consequently, the atomic coordination intimately correlates with the degree of ionicity or covalency of the material. Based on this principle, materials with similar chemical compositions can be successfully categorized into different coordination groups. However, counterexamples recently emerged in complex ternary compounds. For instance, strongly covalent IB-IIIA-VIA₂ compounds, such as AgInS₂, prefer tetrahedrally coordinated structure (TCS), while strongly ionic IA-VA-VIA₂ compounds, such as NaBiS₂, would favor octahedrally coordinated structure (OCS). One naturally expects that IB-VA-VIA₂ compounds with intermediate ionicity or covalency, such as AgBiS₂, should then have a mix-coordinated structure (MCS) consisting of covalent AgS₄ tetrahedra and ionic BiS₆ octahedra. Surprisingly, only OCS was observed experimentally for AgBiS₂. To resolve this puzzle, we perform first-principles studies of the phase stabilities of ternary compounds at finite temperatures. We find that AgBiS₂ indeed prefers MCS at the ground state, in agreement with the typical expectation, but under experimental synthesis conditions disordered OCS becomes energetically more favorable because of its low mixing energy and high configurational entropy. This dataset includes structural information for the MCS and OCS configurations of ABX₂ compounds, along with the principal input data used for each calculation.

Materials Cloud sections using this data

Files

File name	Size	Description
upload-MaterialCloud.zip MD5md5:32f51fb7957f170f5365acc267e38bf7	93.9 KiB	This dataset includes structural information for the MCS and OCS configurations of ABX2 compounds, along with the principal input data used for each calculation.
README.md MD5md5:a2b8e8e70640058281f3d11dfe915d1c	1.6 KiB	upload file description

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External references

Keywords

first principles VASP grand canonical Monte Carlo