Jakse N, Pasturel A
Sciences et Ingénierie des Matériaux et Procédés, UMR CNRS 5266, Grenoble Université Alpes, BP 75, 38402 Saint-Martin d'Hères Cedex, France.
Sci Rep. 2016 Feb 10;6:20689. doi: 10.1038/srep20689.
Understanding how dynamic properties depend on the structure and thermodynamics in liquids is a long-standing open problem in condensed matter physics. A very simple approach is based on the Dzugutov contribution developed on model fluids in which a universal (i.e. species-independent) connection relates the pair excess entropy of a liquid to its reduced diffusion coefficient. However its application to "real" liquids still remains uncertain due to the ability of a hard sphere (HS) reference fluid used in reducing parameters to describe complex interactions that occur in these liquids. Here we use ab initio molecular dynamics simulations to calculate both structural and dynamic properties at different temperatures for a wide series of liquid metals including Al, Au, Cu, Li, Ni, Ta, Ti, Zn as well as liquid Si and B. From this analysis, we demonstrate that the Dzugutov scheme can be applied successfully if a self-consistent method to determine the packing fraction of the hard sphere reference fluid is used as well as the Carnahan-Starling approach to express the excess entropy.
理解液体的动力学性质如何依赖于结构和热力学是凝聚态物理中一个长期存在的开放性问题。一种非常简单的方法基于在模型流体上发展起来的祖古托夫贡献，其中一种通用的（即与物种无关的）联系将液体的对超额熵与其约化扩散系数关联起来。然而，由于用于约化参数的硬球（HS）参考流体描述这些液体中发生的复杂相互作用的能力，其在“真实”液体中的应用仍然不确定。在这里，我们使用从头算分子动力学模拟来计算包括铝、金、铜、锂、镍、钽、钛、锌以及液态硅和硼在内的一系列液态金属在不同温度下的结构和动力学性质。通过这种分析，我们证明，如果使用自洽方法来确定硬球参考流体的填充率以及用卡纳汉 - 斯塔林方法来表示超额熵，那么祖古托夫方案可以成功应用。
