Yoon Tae Jun, Ha Min Young, Lee Won Bo, Lee Youn-Woo
School of Chemical and Biological Engineering, Institute of Chemical Processes, Seoul National University, Seoul 08826, South Korea.
J Chem Phys. 2019 Apr 21;150(15):154503. doi: 10.1063/1.5086467.
This work proposes a classification algorithm based on the radical Voronoi tessellation to define the Widom delta, supercritical gas-liquid coexistence region, of polyatomic molecules. Specifically, we use a weighted mean-field classification method to classify a molecule into either gaslike or liquidlike. Classical percolation theory methods are adopted to understand the generality of the structural transition and to locate the Widom delta. A structural analysis on various supercritical fluids shows that the proposed method detects the influence of the attractive interaction on the structural transition of supercritical fluids. Moreover, we demonstrate that the supercritical gas-liquid coexistence region of water overlaps with the ridges of the response function maxima. From the pressure-temperature relation, a three-parameter corresponding state theorem is derived, which states that the fraction of gaslike molecules of a substance is equal to that of another if their reduced pressure, reduced temperature, and the critical compressibility factor are the same.
这项工作提出了一种基于自由基Voronoi镶嵌的分类算法，以定义多原子分子的维登姆δ，即超临界气液共存区域。具体而言，我们使用加权平均场分类方法将分子分类为气态或液态。采用经典渗流理论方法来理解结构转变的普遍性并定位维登姆δ。对各种超临界流体的结构分析表明，所提出的方法检测到了吸引相互作用对超临界流体结构转变的影响。此外，我们证明了水的超临界气液共存区域与响应函数最大值的脊线重叠。从压力 - 温度关系中，推导出了一个三参数对应状态定理，该定理指出，如果两种物质的对比压力、对比温度和临界压缩因子相同，那么它们气态分子的分数也相等。
