第一性理论研究60～160GPa下固态氢结构稳定性

Structural Stability of the Solid Hydrogen Structures by First Principles Under 60～160 GPa

为研究固态氢结构在60~160GPa压力范围内的结构稳定性,采用第一性原理方法,计算了在60~160GPa压力范围内固态氢Ⅱ相P6_3/m、P2_1/c、P6_3/mmc、Pca2_1和Ⅲ相C2/c 5个结构的热力学和动力学稳定性.计算结果表明,P6_3/m、C2/c和Pca2_1为候选结构,Pca2_1、P6_3/m和C2/c结构分别在60~78、78~90GPa和116~160GPa的3个压力区间内稳定存在.

To research the structural stability of the solid hydrogen structures, the thermodynamic and dynamic properties of the solid hydrogen structures of Ⅱ phase P63/m,P21/c,P63/mmc,Pca21 and Ⅲ phase C2/c were calculated by first-principles calculations under 60-160GPa.The results suggest that that only P63/m,C2/c and Pca21 are competitive structures.The Pca21,P63/m,and C2/c structures can stably exist in the pressure range 60-78,78-90GPa,and 116-160GPa,respectively.