金属铑的反演势构建和应用

采用第一性原理方法，计算得到铑的内聚能曲线；基于陈氏晶格反演理论，将内聚能进行反演得到其晶格反演对势曲线；采用本文提出的双指数型势函数对反演对势曲线进行拟合，获得该函数的精确解析式。为了验证该对势函数的有效性，分别采用第一性原理方法、嵌入原子势方法以及反演对势方法，计算铑的声子谱，计算结果表明，反演对势可以有效地反映原子间相互作用。结合玻尔兹曼分布函数及势函数的解析式，利用自编程序计算得到在不同温度下铑的晶格振动平均位移的数值解，同时得到在室温条件下铑的线膨胀系数，体弹性模量和格林乃森常数等物理量，计算结果与实验数据基本符合，说明构建的铑的反演对势是准确有效的。

The construction and applications of the lattice inversion potential for rhodium metal

The lattice cohesive curve of rhodium was obtained through first-principles calculations. The inversion pair potential curve was generated by inverting the cohesive energy based on Chen''s lattice inversion theory. The double-exponential potential function proposed in this paper was used to fit the inversion potential curve, and the accurate pair potential function was obtained. The phonon spectra of rhodium was calculated through using the inversion potential data, the EAM (embedded atom method) potential theory and first principle method to verify the reliability of the inversion potential function. The calculation results showed that the inversion pair potential effectively reflect the interatomic interaction. The method combining Boltzmann statistics equation with accuracy fitting of lattice cohesive energy curve at different temperature was proposed to calculate the thermal expansion coefficient, the bulk modulus and Grüneisen constant at room temperature. The calculated results were consistent with the experiment results, indicating that the constructed inversion potential of rhodium was accurate and effective.