The pressure effects on lattice parameter, atomic mean-square displacement and elastic moduli (Young’s modulus, shear modulus and bulk modulus) of solid argon have been studied based on the so-called statistical moment method in statistical mechanics. The analytical expressions of these thermodynamic and elastic quantities have been derived. Numerical calculations up to pressure 85 GPa have been performed for argon by using the Buckingham potential to describe interaction between atoms. Present calculations reveal the strong pressure dependence of the atomic mean-square displacement and elastic moduli of argon crystal, especially at pressure below 10 GPa. However, elastic moduli are almost insensitive to temperature. Our theoretical model validity is demonstrated by the reasonable consistent with previous experimental measurements. This approach proposes an effective method for studying of mechanical and thermodynamic properties of materials at high pressure.

基于统计力学中所谓的统计矩方法，研究了压力对固体氩晶格参数，原子均方位移和弹性模量（杨氏模量，剪切模量和体积模量）的影响。这些热力学和弹性量的解析表达式已被推导。通过使用白金汉势来描述原子之间的相互作用，对氩气进行了高达85 GPa压力的数值计算。当前的计算表明，氩晶体的原子均方位移和弹性模量具有很强的压力依赖性，尤其是在低于10 GPa的压力下。但是，弹性模量对温度几乎不敏感。我们的理论模型的有效性通过与先前实验测量结果的合理一致性得到证明。