自由能方法与零压下Al的熔化温度

利用自由能方法的分子动力学模拟，计算了零压下Al的熔化温度.在计算液相自由能的过程中，采用勒纳-琼斯(LJ)液体作为参考系统，同时将计算结果与Mei和Davenport等人的计算结果进行了比较，计算结果表明：1)选用LJ参考系统使液相自由能的计算时间节省一半，并且不影响熔化温度的计算结果；2)采用不同的埋入原子势(EAM)的分子动力学模拟计算得到的熔化温度与实验值都存在偏差，而就金属Al而言，采用Cai等人的EAM势的熔化温度的计算结果比Mei和Davenport及Morris等人采用的势模型的结果略有改 关键词： 熔化温度 自由能方法 分子动力学模拟

Free energy method and the melting point of aluminum under the zero pressure

In this paper，free energy method is used to calculate the melting poing of Al. We adopt the Lennard-Jones (LJ) liquid as the reference system and compare the calculated results with that of Mei，Davenport，and Morris et al. The calculated results show: (1) Using the LJ reference system，the CPU-time consumed for molecular dynamics simulation is reduced to one half of that of Mei，Davenport，and Morris et al while the results are the same; (2) Errors exist in calculated values of melting point in all molecular dynamics simulations using different versions of empirical embedded-atom-model potentials (EAM). For the metal Al，the calculated result using Cai's EAM potential is improved a little comparing with that using EAM potentials in the simulations of Mei，Davenport，and Morris et al.