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第一原理计算一个悬而未决的难题是预测无序相在有限温度下的热力学性能。作者团队指出该难题的最新解决思路是采用可以处理微观组态的配分函数方法,该方法已成为处理只有一种主要微观组态构成的有序相以及有多种明显的微观组态构成的无序相的关键。结合第一原理声子计算和准简谐近似可以有效地预测任意一个给定微观组态的热力学性质。总结了作者团队在第一原理热力学方面的最新研究进展并具体给出了有序相方面的例子:Li2S,hcp Mg和fcc Ni,以及无序相方面的例子:Cu2Zn Sn S4(CZTS)和fcc Ce。同时指出:1从常用的“相”扩展到“微观组态”开辟了一条定量研究材料相变、热膨胀等异常性能的新途径,而这些异常性能的起源可以追溯到“微观组态构型熵”;2这些微观组态也可以认为是材料基因组的基本组成模块。
The first principle to calculate a pending problem is to predict the thermodynamic properties of a disordered phase at a finite temperature. The team of authors pointed out that the latest solution to this challenge was to use a partition function method that could handle microscopic configurations that had become the solution to the problem of dealing with ordered phases with only one major microstructure and with a number of distinct microstructures The key phase. Combined with the first-principle phonon calculation and quasi-harmonic approximation, the thermodynamic properties of any given microstructure can be effectively predicted. The recent progress made by the author team in thermodynamics of first principles is summarized and examples of ordered phases are given: Li2S, hcp Mg and fcc Ni, and examples of disordered phases: Cu2Zn Sn S4 (CZTS) and fcc Ce. At the same time, it is pointed out that the extension of a common “phase” to “microscopic configuration” opens up a new way to quantitatively study the abnormal properties such as phase transformation and thermal expansion of materials, and the origin of these abnormal properties can be traced back to “microscopic Configuration configuration entropy ”; 2 these microscopic configuration can also be considered as the basic component of the material genome module.