L-J流体扩散系数的分子动力学模拟

Molecular dynamics simulation of Lennard-Jonesfluid diffusion coefficients

采用分子动力学 (MD)模拟的方法 ,计算了模型流体氩及氩 /氪溶液的自扩散系数和互扩散系数 .计算结果表明 ,对不同状态下氩的自扩散系数的计算与实验结果符合较好 ,误差在 1 0 %左右 ;采用Green Kubo法和Einstein法计算的扩散系数相等 .氩 /氪溶液的理想性较好 ,由径向分布函数计算得到热力学因子Q的数值为 1 .0 3 .

Molecular dynamics simulations were carried out for mixtures of Lennard-Jones fluids. Self-diffusion coefficients and mutual diffusion coefficients were obtained for Ar and Ar/Kr mixture. The pressure and temperature dependencies of the self-diffusion coefficients were investigated. The diffusion coefficients calculated from the Green-Kubo integral over velocity correlation function and from the Einstein relation for the mean square displacement were equivalent. The value of thermodynamic factor obtained from the radial distribution function was 1.03, and the mixture of Ar/Kr system was near ideal solute.