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arXiv 0705.1069cond-mat.softcond-mat.stat-mechphysics.chem-ph
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可穿透球体流体的低温和高温近似。与蒙特卡罗模拟和积分方程理论的比较

Low-temperature and high-temperature approximations for penetrable-sphere fluids. Comparison with Monte Carlo simulations and integral equation theories

Alexandr Malijevsky, Santos B. Yuste, Andres Santos

摘要:

高分子链在良溶剂中的稀溶液中的两体相互作用可以用有效有界势来模拟,其中最简单的是可穿透球(PS)。在本文中,我们构建了两个简单的分析理论的PS流体的结构特性:低温(LT)近似,这可以被看作是一个扩展到PS的著名的解决方案的Percus-Yevick(PY)方程的硬球,和高温(HT)近似的基础上的精确渐近行为的极限温度。蒙特卡罗模拟的温度和密度范围很广,以评估这两种理论的有效性。据发现,尽管它们的简单性,HT和LT近似表现出公平的协议与仿真数据在各自的适用范围内,使它们相互补充。的PY和超网链近似的数值解的比较也进行了,后者表现出非常好的性能,除了在低温下的核心内。

英文摘要:

The two-body interaction in dilute solutions of polymer chains in good solvents can be modeled by means of effective bounded potentials, the simplest of which being that of penetrable spheres (PSs). In this paper we construct two simple analytical theories for the structural properties of PS fluids: a low-temperature (LT) approximation, that can be seen as an extension to PSs of the well-known solution of the Percus-Yevick (PY) equation for hard spheres, and a high-temperature (HT) approximation based on the exact asymptotic behavior in the limit of infinite temperature. Monte Carlo simulations for a wide range of temperatures and densities are performed to assess the validity of both theories. It is found that, despite their simplicity, the HT and LT approximations exhibit a fair agreement with the simulation data within their respective domains of applicability, so that they complement each other. A comparison with numerical solutions of the PY and the hypernetted-chain approximations is also carried out, the latter showing a very good performance, except inside the core at low temperatures.

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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