Abstract

Drawbacks of some methods known from the literature for determining four parameters of the Mie–Lennard-Jones pairwise interatomic potential as applied to crystals are pointed out. A new method for parametrization of the potential by thermoelastic properties of the crystal is proposed. The method determines the parameters by the best agreement of the calculated values with experimental data such as (1) the sublimation energy of the crystal at the zero values of the temperature (T = 0 K) and pressure (P = 0), (2) the thermal expansion coefficient and the isothermal modulus of elasticity measured at P = 0 and T = 300 K, and (3) the dependence of the isotherm curve T = 300 K of the equation of state on the volume P(300 K, V). The method was verified for iron and gold and showed good results. Further, the proposed method was applied to determine the parameters of the interatomic potential for refractory metals, viz., Nb, Ta, Mo, and W. The results obtained also allowed for more accurate determination of the sublimation energy, the Debye temperature, and the surface energy of the above metals.

中文翻译：

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成对原子间电势的参数化方法

摘要

指出了一些已知的方法的缺点，这些方法确定了应用于晶体的Mie-Lennard-Jones成对原子间电势的四个参数。提出了一种通过晶体的热弹性特性对电势进行参数化的新方法。该方法通过计算值与实验数据的最佳一致性来确定参数，例如（1）在温度（T = 0 K）和压力（P = 0）的零值处晶体的升华能量，（2 ）在P = 0和T = 300 K时测得的热膨胀系数和等温弹性模量，以及（3）等温线T的依赖性=体积P上的状态方程的300 K（300 K，V）。对该方法进行了铁和金的验证，结果良好。此外，所提出的方法用于确定难熔金属的原子间电势参数，即Nb，Ta，Mo和W。获得的结果还可以更准确地确定升华能量，德拜温度和上述金属的表面能。