在高压下CrB4 的结构和电子性质的第一性原理计算

First-principles calculations of structural and electronic properties of CrB4 under high pressure

摘要:

该论文对新合成超硬材料CrB4 的结构和电子性质从0 GPa到100 GPa的压力范围内，采用密度泛函理论下的第一性原理计算进行了详细的理论研究. 在零压力下的结果与现有的理论和实验值吻合得很好. 计算了CrB4 的结构，键长，B–B、Cr–B键的Mulliken重叠布居，态密度（DOS）和PDOS等随压力的依赖，并进行了讨论. 计算出的结构性质随压力的依赖表明，结构参数和CrB4 共价键对压力不敏感，有力地支持了CrB4化合物的高硬度是来自于B–B笼这一特点.

Abstract:

We present a detailed theoretical study for the structural and electronic properties of the new synthesized hard material CrB4 under pressure ranging from 0 GPa to 100 GPa by first-principles calculations with density functional theory in this paper. The results at zero pressure are in good agreement with the available theoretical and experimental values. The pressure dependence of structure, bond length , the Mulliken overlap population of B–B bonds and Cr–B bond, density of states (DOS) and PDOS are successfully calculated and discussed. The calculated pressure dependence of structural property shows that both structural parameters and covalent bonds of CrB4 are insensitive to the pressure, the results strongly support that the high hardness of CrB4 compounds is derived from the feature of B–B bonds cage.