Wang Dian-Hui, Zhou Huai-Ying, Hu Chao-Hao, Zhong Yan, Oganov Artem R, Rao Guang-Hui
School of Materials Science and Engineering, Central South University, Changsha 410083, P. R. China.
School of Materials Science and Engineering, Central South University, Changsha 410083, P. R. China and Guangxi Key Laboratory of Information Materials, Guilin University of Electronic Technology, Guilin 541004, P. R. China.
Phys Chem Chem Phys. 2017 Mar 22;19(12):8471-8477. doi: 10.1039/c6cp08900c.
To clarify controversial structures and phase stability in the Li-B system, we predicted energetically favorable compounds and crystal structures of the Li-B binary system at ambient pressure, mainly including LiB, LiB, and LiB, from ab initio evolutionary structure simulations and further investigated physical properties of stable Li-B compounds using first-principles methods. Metallic LiB, predicted in our simulations, has trigonal symmetry with space group R32 and contains linear B chains, but its superconducting T is low according to the electron-phonon coupling calculations. Orthorhombic LiB (Pnma) and tetragonal LiB (P4/mbm) are zero-gap semiconductors; LiB is a Dirac semimetal, and both LiB and LiB are promising thermoelectric materials.
为了阐明Li-B体系中存在争议的结构和相稳定性，我们通过从头算演化结构模拟预测了常压下Li-B二元体系能量上有利的化合物和晶体结构，主要包括LiB、LiB和LiB，并使用第一性原理方法进一步研究了稳定Li-B化合物的物理性质。我们的模拟预测的金属LiB具有三方对称性，空间群为R32，包含线性B链，但根据电子-声子耦合计算，其超导转变温度较低。正交晶系的LiB（Pnma）和四方晶系的LiB（P4/mbm）是零带隙半导体；LiB是一种狄拉克半金属，LiB和LiB都是很有前景的热电材料。
