Melting temperature is a fundamental material property and is defined as the temperature at which the solid and liquid phases have the same free energy. However, there is no systematic study employing atomic simulations to calculate melting temperature using this definition. Here, molecular dynamics simulations and nonequilibrium thermodynamic integration methods are combined to calculate the melting temperature of Al and Cu. Results show that to accurately obtain the melting temperature, the model size should be considered carefully because the free energies of both solid and liquid phases are inversely proportional to the model size, causing a model size dependence on the calculated melting temperature. In addition, the melting temperature for various (semi-) empirical potential models for Al and Cu is calculated and verified against experimental values to provide guidelines for the choice of potential models for simulation-based problems relevant to the solid–liquid phase transformation.

中文翻译：

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使用非平衡热力学积分方法计算熔化温度

熔化温度是材料的基本特性，定义为固相和液相具有相同自由能的温度。然而，还没有系统的研究利用原子模拟来使用这个定义来计算熔化温度。这里，结合分子动力学模拟和非平衡热力学积分方法来计算Al和Cu的熔化温度。结果表明，为了准确获得熔化温度，应仔细考虑模型尺寸，因为固相和液相的自由能与模型尺寸成反比，导致模型尺寸依赖于计算的熔化温度。此外，还根据实验值计算并验证了 Al 和 Cu 的各种（半）经验势模型的熔化温度，为与固液相变相关的基于模拟的问题选择势模型提供指导。