Validity of compressibility equation and Kirkwood-Buff theory for crystalline matter
Validity of compressibility equation and Kirkwood-Buff theory for crystalline matter
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结晶物质的压缩性方程和 Kirkwood-Buff 理论的有效性
DOI：
10.1103/physreve.103.l061301
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发表时间：
2021
影响因子：
2.4
通讯作者：
Peter Krueger
中科院分区：
文献类型：
--
作者：
河野淳也;Peter Krueger
径向对分布函数上的体积积分，即所谓的Kirkwood-Buff积分（KBIs），通过将结构信息与热力学信息联系起来，在溶液理论中发挥着核心作用。最简单的例子是压缩性方程，这是流体统计力学中的一个基本关系。到目前为止，KBI理论还不能应用于晶体，因为当以标准方式计算时，积分会强烈发散。我们解决了发散问题，并推广KBI理论的结晶物质，通过使用最近提出的有限体积理论。对于具有简谐相互作用的晶体，我们导出了有限温度下对分布函数峰形的解析表达式。由此我们证明了压缩性方程在谐波晶体中完全成立。
Volume integrals over the radial pair-distribution function, so-called Kirkwood-Buff integrals (KBIs), play a central role in the theory of solutions by linking structural with thermodynamic information. The simplest example is the compressibility equation, a fundamental relation in statistical mechanics of fluids. Until now, KBI theory could not be applied to crystals because the integrals strongly diverge when computed in the standard way. We solve the divergence problem and generalize KBI theory to crystalline matter by using the recently proposed finite-volume theory. For crystals with harmonic interaction, we derive an analytic expression for the peak shape of the pair-distribution function at finite temperature. From this we demonstrate that the compressibility equation holds exactly in harmonic crystals.