5种金属高压熔化曲线的理论计算

摘要

Ab-initio calculation method is employed to determine the potential functions and the unknown parameters in pair-potential-based mean filed model for metals.Using the mean fields constructed from the potential functions,the vibration free volumes of atoms of metals Al,Cu,Ni,Na,and K at melting points are evaluated.The results indicate that the widely used hypothesis that the ratio of vibration free volume to the primitive cell volume of atoms in melting curve is a constant,is not correct.We provide a ratio model which can be usd to obtain much more accurate results of melting curve.%利用从头算法确定了基于对势的平均场模型中的未知势参数,从而确定了势函数,然后利用得到的势函数构建平均场,进一步计算了5种金属材料Al,Cu,Ni,Na,K在熔点处原子振动的自由体积.计算的结果表明,熔化曲线上原子振动的自由体积与原子晶胞体积之比是常数这一假设并不普遍适用：对该假设修正后可以比较准确地计算材料的熔化曲线.