School of Physics, Beijing Institute of Technology, Beijing 100081, People's Republic of China.
Department of Engineering Mechanics, Center for Nano and Micro Mechanics, Tsinghua University, Beijing 100084, People's Republic of China.
J Chem Phys. 2019 Sep 7;151(9):094503. doi: 10.1063/1.5112794.
We develop a ReaxFF reactive force field used for the molecular dynamics simulations of thermophysical properties of liquid Cu and Zr metals. The ReaxFF parameters are optimized by fitting to the first-principles density-functional calculations on the equations of state for bulk crystal structures and surface energies. To validate the force field, we compare the ReaxFF results with those from experiments and embedded-atom-method (EAM) potentials. We demonstrate that the present ReaxFF force field well represents structural characteristics and diffusion behaviors of elemental Cu and Zr up to high-temperature liquid regions. It reasonably reproduces the thermodynamic processes associated with crystal-liquid interface. In particular, the equilibrium melting temperatures show better agreement with experimental measurements than the results from EAM potentials. The ReaxFF reactive force field method exhibits a good transferability to the nonreactive processes of liquid systems.
我们开发了一个 ReaxFF 反应力场，用于液态 Cu 和 Zr 金属热物理性质的分子动力学模拟。通过对体相晶体结构和表面能的第一性原理密度泛函计算进行拟合，优化了 ReaxFF 参数。为了验证力场，我们将 ReaxFF 的结果与实验和嵌入原子法（EAM）势的结果进行了比较。结果表明，该 ReaxFF 力场很好地描述了元素 Cu 和 Zr 的结构特征和扩散行为，直至高温液态区域。它合理地再现了与晶体-液体界面相关的热力学过程。特别是，平衡熔化温度与实验测量值的吻合程度要好于 EAM 势的结果。ReaxFF 反应力场方法对液体系统的非反应过程具有良好的可转移性。
