用离子重叠-压缩模型对碱金属氢化物晶体中的H-离子压缩规律的研究

A Study on the Compression Law of H- Ions in the Alkali Hydride Crystals by the Ionic Overlap-Compression Model

Institute of High-Temperature and High-Pressure Physics, Chengdu University of Science and Technology, Chengdu 610065, China

摘要: 利用离子重叠-压缩模型以及晶体结合能的变分计算方法，计算了碱金属氢化物LiH、NaH和KH晶体中描述H-离子状态的参数及其相对离子半径随压力的变化规律。得到的结果表明，未加外压力时，晶体中的H-离子相对其孤立状态就已明显被压缩，而且压缩变化规律几乎与具体的晶体结构无关。这两点结论物理上都是合理的，并间接被同时得到的物态方程及结构相变压力的理论值与实验结果符合得非常好这一事实所证实。
- H-离子 /
- 碱金属氢化物 /
- 压缩规律
Abstract: By using the ionic overlap-compression model, the parameter describing the state of H- by ions in the alkali hydride crystals (LiH, NaH and KH) was calculated by variation method. Then the numerical relations of and the relative radius of H- ions with the pressure were determined. The results show that the compression of H- ions has occurred before the pressure is added, and the compression law almost has nothing to do with the crystal structures. These two points are physically reasonable and were confirmed indirectly by the experiments.
- H- ion /
- alkali hydrides /
- compression behavior