Thermomechanical properties of the WCA–Lennard-Jones model system in its fluid and solid states
Thermomechanical properties of the WCA–Lennard-Jones model system in its fluid and solid states
复制标题
WCA–Lennard-Jones 模型系统在流体和固态下的热机械特性
DOI：
10.1016/s0378-4371(97)00612-2
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发表时间：
1998
影响因子：
3.3
通讯作者：
Harald Voigt
中科院分区：
文献类型：
--
作者：
S. Hess;M. Kröger;Harald Voigt
WCA-Lennard-Jones 模型系统在流体和 fcc 晶态下的热机械特性是通过分子动力学 (MD) 模拟计算的，包括恒体积 (NVT) 和恒压 (NPT)。对于一些选定的温度，压力、能量、比热、体积和剪切弹性系数以及其他量的数据以图形形式呈现为密度的函数。将那些可以从流体状态下的自由能计算出的量与基于修正的卡纳汉-斯塔林 (CS) 理论的理论表达式进行比较。这涉及第二维里系数和与温度相关的粒子有效体积，对此讨论了各种表达式。对于有效体积的简单特定选择，理论与模拟之间存在良好的一致性。对于这种情况，附加的热力学量以图形方式显示。附录中还以表格形式给出了一些 MD 数据。
Thermomechanical properties of the WCA–Lennard-Jones model system in its fluid and fcc crystalline states are computed via molecular dynamics (MD) simulations, both with constant volume (NVT) and with constant pressure (NPT). Data for the pressure, energy, specific heat, bulk and shear elasticity coefficients, and for other quantities are presented in graphical form, as functions of the density, for a few selected temperatures. Those quantities which can be computed from the free energy, in the fluid state, are compared with theoretical expressions based on a modified Carnahan–Starling (CS) theory. This involves the second virial coefficient and a temperature-dependent effective volume of a particle for which various expressions are discussed. Good agreement between theory and simulation is found for a simple specific choice of the effective volume. Additional thermodynamical quantities are displayed graphically for this case. Some MD data are also given in tabular form in the appendix.