Pentaheptite diamond: a new carbon allotrope

Chuang Zhang; Xigui Yang; Ruoyun Lv; Chaofan Lv; Jinxu Qin; Hang Liu; Jinhao Zang; Lin Dong; Chong-Xin Shan

doi:10.1088/1361-648X/ac506e

Pentaheptite diamond: a new carbon allotrope

J Phys Condens Matter. 2022 Mar 1;34(18). doi: 10.1088/1361-648X/ac506e.

Authors

Chuang Zhang¹, Xigui Yang¹, Ruoyun Lv¹, Chaofan Lv¹, Jinxu Qin¹, Hang Liu¹, Jinhao Zang¹, Lin Dong¹, Chong-Xin Shan¹

Affiliation

¹ Henan Key Laboratory of Diamond Optoelectronic Materials and Devices, Key Laboratory of Material Physics, Ministry of Education, School of Physics and Microelectronics, Zhengzhou University, Zhengzhou 450052, People's Republic of China.

PMID: 35100570
DOI: 10.1088/1361-648X/ac506e

Abstract

The search forsp³-hybridized carbon allotropes other than diamond has attracted extensive interest because of their fascinating properties. In this paper, an orthorhombic carbon phase insp³bonding, named pentaheptite diamond, by combining the particle swarm optimization method with first-principles calculations has been predicted. The phonon spectra, total energy and elastic constants calculations of the pentaheptite diamond confirm its dynamical, thermal and mechanical stability at zero pressure, respectively. It possesses a high bulk modulus of 385 GPa and Vickers hardness of 72.6 GPa, comparable to diamond. Electronic band structure calculations show that the pentaheptite diamond has a direct band gap of 4.18 eV.

Keywords: carbon allotrope; first-principles calculations; superhard material.