Role of the Barker–Henderson diameter in thermodynamics
Role of the Barker–Henderson diameter in thermodynamics
复制标题
巴克-亨德森直径在热力学中的作用
DOI：
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发表时间：
2002
期刊：
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通讯作者：
Yiping Tang
中科院分区：
文献类型：
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作者：
Yiping Tang
讨论了热力学对Lennard-Jones(LJ)势的Barker-Henderson(BH)直径的敏感性，包括它在计算中的近似性和合理性的改进。在此基础上，研究了LJ流体、LJ链和LJ链混合物的压强和内能。结果表明，对于纯流体，内能对直径的近似值比压力更敏感，而对于混合物，压力和内能对直径都非常敏感。我们还发现，Cotterman等人给出的近似表达式。(1986)覆盖了最广泛的温度范围。还分析了BH直径在很高的温度和密度下的合理性。通过对亥姆霍兹自由能的泛函展开，我们得出结论：依赖于密度的BH直径从根本上来说更合适。计算结果与原井筒直径在正常情况下的结果基本一致，并与原井筒直径进行了对比。
Sensitivity of thermodynamics to the Barker–Henderson (BH) diameter for the Lennard-Jones (LJ) potential is discussed, which covers both its approximation in calculation and improvement in rationality. With regarding to the approximation, pressure and internal energy for the LJ fluid, LJ chains and LJ chain mixtures are investigated. It is found that internal energy is much more sensitive to an approximation to the diameter than pressure for pure fluids, and both pressure and internal energy are very sensitive to the diameter for mixtures. It is also found that the approximating expression given by Cotterman et al. (1986) covers the widest range of temperatures. The rationality of the BH diameter itself at very high temperatures and densities is also analyzed. Through a functional expansion of Helmholtz free energy, we conclude that a density-dependent BH diameter is fundamentally more appropriate. The proposed diameter yields almost the same results as the original BH diameter at normal conditions and re...