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使用第一性原理方法结合平均场模型研究了压力从0到150GPa、温度从0到1500K,金属铍六角密排结构(hcp)的热力学性质,包括铍的常态性质,等温高压物态方程,以及常压下平衡体积、体弹模量随温度的变化,Hugoniot曲线等.0K物态方程由广义梯度近似下的密度泛函理论计算,粒子热运动的贡献由平均场模型计算.由于铍的Debye温度比较高,计算自由能时考虑了零点振动能修正.计算结果与已有的静力学和冲击波实验数据符合得非常好.
The thermodynamic properties of hexagonal metal hexagonal close-packed structure (hcp) at pressures from 0 to 150 GPa and temperatures from 0 to 1500 K were investigated using the first-principles method coupled with the mean field model, including the isotropic nature of beryllium, the isothermal high-pressure state equation, and Equilibrium volume at atmospheric pressure, change of body elastic modulus with temperature, Hugoniot curve, etc. The equation of state of 0 K is calculated by the density functional theory under the generalized gradient approximation, and the contribution of the particle thermal motion is calculated by the mean field model. Since Debye The temperature is relatively high, and the zero-point vibration energy correction is taken into account when calculating the free energy.The calculation results are in good agreement with the existing experimental data of static and shock wave.