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arXiv 0705.1230cond-mat.softcond-mat.stat-mech
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通过计算机模拟直接计算界面张力:自由连接的切向硬球链的结果

Direct calculation of interfacial tensions from computer simulation: Results for freely jointed tangent hard sphere chains

Luis G. MacDowell, Pawel Bryk

摘要:

我们开发了一种方法来计算表面自由能的概率分布的基础上徘徊接口。使用一个简单的扩展的NpT采样,我们允许界面区域随机探测可用的空间和评估的表面自由能从直方图分析和相应的平均值。该方法适用于研究系统的连续或不连续的潜力,因为它不需要显式的维里评估。将该算法与已知的Lennard-Jones和Square Well流体的表面张力以及珠-弹簧模型的界面张力的计算结果进行了比较,发现两者吻合较好,并计算了宽链长和密度范围内的切向硬球链在无热壁面上的界面张力.结果进行了比较,与三种不同的理论方法,标度粒子理论,于和吴密度泛函理论和解析近似的基础上,后者的方法。而SPT只产生定性的结果,最后两种方法被发现产生非常好的协议与模拟。

英文摘要:

We develop a methodology for the calculation of surface free energies based on the probability distribution of a wandering interface. Using a simple extension of the NpT sampling, we allow the interface area to randomly probe the available space and evaluate the surface free energy from histogram analysis and the corresponding average. The method is suitable for studying systems with either continuous or discontinuous potentials, as it does not require explicit evaluation of the virial. The proposed algorithm is compared with known results for the surface tension of Lennard--Jones and Square Well fluid, as well as for the interface tension of a bead--spring polymer model and good agreement is found. We also calculate interfacial tensions of freely jointed tangent hard sphere chains on athermal walls for a wide range of chain lengths and densities. The results are compared with three different theoretical approaches, Scaled Particle Theory, the Yu and Wu density functional theory and an analytical approximation based on the latter approach. Whereas SPT only yields qualitative results, the last two approaches are found to yield very good agreement with simulations.

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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