Indication of Low-Energy BC5 Structures

• 作者: 邵熙
• 来源期刊: 中国物理快报(英文版)
• 学科: 化学
• 关键词: 亚稳态结构 低能量 计算验证 电荷转移 类金刚石 晶体结构 第一原理 能源结构
• 年，卷（期）: 2010,（1）
• 页码范围: 182-185
• 页数: 4页
• 分类号: O641.4 TB383
• 语种: 英文

摘要

The Bond counting rule is proved to be an important and effective criterion for searching low-energy metastable structures for ternary boron carbon nitrogen (B-C-N) compounds. The Bond counting rule, however, has its limitations for the binary diamond-like or ternary B-C-N polymorphs with the same bond ratio. First-principles calculations validate that the Mulliken charge difference may serve as an indication of low-energy crystal structures, and clarify the energy difference among those polymorphs to some extent. For example, we predict two ground state phases ofsuperhard BC5 (named as I-BC5 and II-BC5), which are 0.28 and 0.27eV/formula lower in energy than the P3m1 structure reported recently in the literature [Calandra et al. Phys. Rev. Lett. 101(2008)016401], respectively. The charge transfer analysis reveals that the smaller Mulliken charge difference for the same kind of element will result in more stable structures.