Complex Low Energy Tetrahedral Polymorphs of Group IV Elements from First Principles

He, Chaoyu; Shi, Xizhi; Clark, Stewart J.; Li, Jin; Pickard, Chris J.; Ouyang, Tao; Zhang, Chunxiao; Tang, Chao; Zhong, Jianxin

doi:10.1103/physrevlett.121.175701

Complex Low Energy Tetrahedral Polymorphs of Group IV Elements from First Principles

He, Chaoyu; Shi, Xizhi; Clark, Stewart J.; Li, Jin; Pickard, Chris J.; Ouyang, Tao; Zhang, Chunxiao; Tang, Chao; Zhong, Jianxin

Authors

Chaoyu He

Xizhi Shi

Professor Stewart Clark s.j.clark@durham.ac.uk
Professor

Jin Li

Chris J. Pickard

Tao Ouyang

Chunxiao Zhang

Chao Tang

Jianxin Zhong

Abstract

The energy landscape of carbon is exceedingly complex, hosting diverse and important metastable phases, including diamond, fullerenes, nanotubes, and graphene. Searching for structures, especially those with large unit cells, in this landscape is challenging. Here we use a combined stochastic search strategy employing two algorithms (ab initio random structure search and random sampling strategy combined with space group and graph theory) to apply connectivity constraints to unit cells containing up to 100 carbon atoms. We uncover three low energy carbon polymorphs ( P b a m − 32 , P 6 / m m m , and I ¯ 4 3 d ) with new topologies, containing 32, 36, and 94 atoms in their primitive cells, respectively. Their energies relative to diamond are 96, 131, and 112 meV / atom , respectively, which suggests potential metastability. These three carbon allotropes are mechanically and dynamically stable, insulating carbon crystals with superhard mechanical properties. The I ¯ 4 3 d structure possesses a direct band gap of 7.25 eV, which is the widest gap in the carbon allotrope family. Silicon, germanium, and tin versions of P b a m − 32 , P 6 / m m m , and I ¯ 4 3 d also show energetic, dynamical, and mechanical stability. The computed electronic properties show that they are potential materials for semiconductor and photovoltaic applications.

Citation

He, C., Shi, X., Clark, S., Li, J., Pickard, C. J., Ouyang, T., …Zhong, J. (2018). Complex Low Energy Tetrahedral Polymorphs of Group IV Elements from First Principles. Physical Review Letters, 121(17), Article 175701. https://doi.org/10.1103/physrevlett.121.175701

Journal Article Type	Article
Acceptance Date	Oct 10, 2018
Online Publication Date	Oct 26, 2018
Publication Date	Oct 26, 2018
Deposit Date	Oct 29, 2018
Publicly Available Date	Oct 30, 2018
Journal	Physical Review Letters
Print ISSN	0031-9007
Electronic ISSN	1079-7114
Publisher	American Physical Society
Peer Reviewed	Peer Reviewed
Volume	121
Issue	17
Article Number	175701
DOI	https://doi.org/10.1103/physrevlett.121.175701
Related Public URLs	https://arxiv.org/pdf/1810.04896.pdf

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Copyright Statement
Reprinted with permission from the American Physical Society: He, Chaoyu, Shi, Xizhi, Clark, Stewart J., Li, Jin, Pickard, Chris J., Ouyang, Tao, Zhang, Chunxiao, Tang, Chao & Zhong, Jianxin (2018). Complex Low Energy Tetrahedral Polymorphs of Group IV Elements from First Principles. Physical Review Letters 121(17): 175701. © (2018) by the American Physical Society. Readers may view, browse, and/or download material for temporary copying purposes only, provided these uses are for noncommercial personal purposes. Except as provided by law, this material may not be further reproduced, distributed, transmitted, modified, adapted, performed, displayed, published, or sold in whole or part, without prior written permission from the American Physical Society.