论文标题
硬球和方孔流体的Verlet闭合关系的进化优化
Evolutionary optimization of the Verlet closure relation for the hard-sphere and square-well fluids
论文作者
论文摘要
使用多种闭合关系选择，用于硬球和方形流体的Ornstein-cernike方程。选择方孔的吸引力范围为$λ= 1.5。尤其是$，对于两种流体，我们主要基于基于verlet闭合关系的三参数版本的解决方案[mol。物理。 42，1291-1302（1981）]。为了找到后者的自由参数，根据可压缩性定义了无约束的优化问题是热力学一致性的条件，并使用进化算法解决了。对于硬球流体，与状态和准确的计算机模拟结果相比，结果表现出良好的一致性；在高密度的情况下，即接近冰冻过渡，可以看到预期的（小）偏差。在方孔流体的情况下，与事件驱动的分子动力学计算机模拟相比，在低和高密度下观察到了良好的一致性。对于中间密度，探索的封闭关系在准确性方面有所不同。我们的发现表明，对优化问题进行修改，例如，包括其他热力学一致性标准可以改善此处探索的流体类型的结果。
The Ornstein-Zernike equation is solved for the hard-sphere and square-well fluids using a diverse selection of closure relations; the attraction range of the square-well is chosen to be $λ=1.5.$ In particular, for both fluids we mainly focus on the solution based on a three-parameter version of the Verlet closure relation [Mol. Phys. 42, 1291-1302 (1981)]. To find the free parameters of the latter, an unconstrained optimization problem is defined as a condition of thermodynamic consistency based on the compressibility and solved using Evolutionary Algorithms. For the hard-sphere fluid, the results show good agreement when compared with mean-field equations of state and accurate computer simulation results; at high densities, i.e., close to the freezing transition, expected (small) deviations are seen. In the case of the square-well fluid, a good agreement is observed at low and high densities when compared with event-driven molecular dynamics computer simulations. For intermediate densities, the explored closure relations vary in terms of accuracy. Our findings suggest that a modification of the optimization problem to include, for example, additional thermodynamic consistency criteria could improve the results for the type of fluids here explored.
