高压下氢化钠弹性和热力学性质的理论研究

本文采用密度泛函理论的赝势平面波方法，对NaH从B1到B2相的相变和这两种相的弹性进行了理论研究.其结果（弹性常数cij、体变模量BS 和剪切模量G）与已有的实验及理论结果吻合较好.与此同时，我们首次得到了不同压力下泊松关系、德拜温度、横（纵）波弹性波速与压强的变化关系.

Theoretical studies of the elastic and thermodynamic properties for sodium hydride under high-pressure

Ab initio calculations of the structural B1-B2 phase transition and the elastic properties of the B1 and B2 phases of NaH have been carried out with the plane-wave pseudopotential density functional theory method.Our calculated values are in agreement with the experimental data and some of the existing model calculations.Under high compressions,the elastic constants cij,the aggregate elastic modulus Bs and G are discussed.Moreover,the variations of Poisson ration,Debye temperature,longitudinal and transverse elastic wave velocities with pressure P have been investigated for the first time.