论文标题
通过不可约的导数方法来预测热物理特性的参数化经验性原子间潜力：$ _2 $和UO $ _2 $的情况
Parameterizing empirical interatomic potentials for predicting thermophysical properties via an irreducible derivative approach: the case of ThO$_2$ and UO$_2$
论文作者
论文摘要
使用分子动力学模拟的经典物理性质预测的准确性取决于原子间电位的质量。在这里，我们介绍了一种经验原子间电位（EIP）的训练方法，该方法非常适合捕获声子和与声子相关的特性。我们的方法是基于对EIP和Born-oppenheimer在密度功能理论（DFT）计算中的二阶和三阶不可约性衍生物的直接比较。不可还原衍生物完全利用空间组对称性，并允许训练无冗余信息。我们在$ _2 $和uo $ _2 $的背景下演示了我们方法的保真度，除了核心壳交互之外，我们还优化了嵌入式原子能方法的参数。我们的EIP提供了与DFT相吻合的热物理特性，并且跑赢大于EIP，用于声子分散和热导率预测。还获得了弗伦克尔对的热膨胀和形成能的合理估计。
The accuracy of classical physical property predictions using molecular dynamics simulations is determined by the quality of the interatomic potentials. Here we introduce a training approach for empirical interatomic potentials (EIPs) which is well suited for capturing phonons and phonon-related properties. Our approach is based on direct comparisons of the second- and third-order irreducible derivatives between an EIP and the Born-Oppenheimer potential within density functional theory (DFT) calculations. Irreducible derivatives fully exploit space group symmetry and allow for training without redundant information. We demonstrate the fidelity of our approach in the context of ThO$_2$ and UO$_2$, where we optimize parameters of an embedded-atom method potential in addition to core-shell interactions. Our EIPs provide thermophysical properties in good agreement with DFT and outperform widely utilized EIPs for phonon dispersion and thermal conductivity predictions. Reasonable estimates of thermal expansion and formation energies of Frenkel pairs are also obtained.
