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用从头算方法优化计算了面心立方铝的电子结构和总能,得到了它在零温下的状态方程和弹性性质.将得到的总能与晶格体积拟合到Debye模型,获得了非平衡态下的Gibbs自由能与温度、压力之间的关系,在此基础上计算了相应的热状态方程,利用Burakovsky-Preston-Silbar(BPS)熔化模型计算了铝的熔化曲线.所有的电子结构和总能计算都是基于局域密度近似(LDA)和广义梯度近似(GGA)的平均得到的.计算得到的铝在高温、高压下的状态方程与一些热力学性质和熔化曲线同冲击波和静高压实验数据在225GPa压力范围内符合良好.
The electronic structure and total energy of face-centered cubic aluminum were calculated by ab initio method, and its state equation and elastic property at zero temperature were obtained. The obtained total energy and lattice volume were fitted to the Debye model, The relationship between Gibbs free energy and temperature and pressure in the equilibrium state was calculated. Based on this, the corresponding thermal equation was calculated, and the melting curve of aluminum was calculated by Burakovsky-Preston-Silbar (BPS) melting model. All the electronic structures And total energy calculations are based on the average of the local density approximation (LDA) and the generalized gradient approximation (GGA). The calculated state equations for aluminum at high temperatures and pressures, along with some thermodynamic properties and melting curves, The experimental data is in good agreement at a pressure of 225 GPa.