第一性理论研究60~160 GPa下固态氢结构稳定性
Structural Stability of the Solid Hydrogen Structures by First Principles Under 60~160 GPa
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摘要: 为研究固态氢结构在60~160 GPa压力范围内的结构稳定性,采用第一性原理方法,计算了在60~160 GPa压力范围内固态氢Ⅱ相P63/m、P21/c、P63/mmc、Pca21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,P63/m、C2/c和Pca21为候选结构,Pca21、P63/m和C2/c结构分别在60~78、78~90 GPa和116~160 GPa的3个压力区间内稳定存在.Abstract: 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 60~160 GPa. 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, 78~90 GPa, and 116~160 GPa, respectively.
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