arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1906.09894cond-mat.soft
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方井流体结构和热力学的解析处理

Analytical treatment of the structure and thermodynamics of the square-well fluid

Jesús Benigno Zepeda-López, Alexis Torres-Carbajal, Pedro Ezequiel Ramírez-González, Magdaleno Medina-Noyola

摘要:

这项工作的主要目标是准确地再现由硬球加方阱(HS + SW)相互作用势建模的吸引系统的结构特性。基于优化的无规相位近似(ORPA),相互作用势的吸引部分被处理为硬球项的微扰。我们能够得到一个解析表达式的结构因子$ S \left( k \right) $再现低密度极限。计算了几种SW流体相的微观结构,并与Monte Carlo(MC)模拟结果进行了比较,结果表明,结构因子在很宽的波矢范围内得到了很好的再现,此外,径向分布函数的接触和不连续值也很好地吻合。此外,我们计算的压力状态方程,并进行了定量分析比较模拟结果发现,在一个大的密度和温度的集合,我们的方法优于其线性形式。此外,我们表明,在这项研究中开发的理论方法工程非常好,许多热力学状态,使我们一个通用的和自信的工具,系统地计算SW流体的结构和热力学。

英文摘要:

The main goal of this work is to accurately reproduce the structural properties of attractive systems modelled by hard-sphere plus square-well (HS+SW) interaction potential. Based on the optimized random phase approximation (ORPA), the attractive part of the interaction potential is treated as a perturbation of the hard-sphere term. We are able to obtain an analytical expression for the structure factor $ S \left( k \right) $ which reproduces the low density limit. The microscopical structure of the fluid phase of several SW fluids is computed and compared with Monte Carlo (MC) simulation results showing that the structure factor is well reproduced in a wide range of wave vectors, in addition, the contact and discontinuity values of the radial distribution function are found to be in good agreement. Additionally, we compute the pressure equation of state and perform a quantitative analysis comparing with simulation results found that in a large set of densities and temperatures our approach outperform its linear form. Furthermore, we show that the theoretical approach developed in this study works very well for many thermodynamic states leading us a versatile and confident tool to systematic compute the structure and thermodynamics of SW fluids.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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