Jamali Seyed Hossein, Bardow André, Vlugt Thijs J H, Moultos Othonas A
Engineering Thermodynamics, Process & Energy Department, Faculty of Mechanical, Maritime and Materials Engineering, Delft University of Technology, Leeghwaterstraat 39, 2628CB Delft, The Netherlands.
Institute of Technical Thermodynamics, RWTH Aachen University, 52056 Aachen, Germany.
J Chem Theory Comput. 2020 Jun 9;16(6):3799-3806. doi: 10.1021/acs.jctc.0c00268. Epub 2020 May 8.
The system-size dependence of computed mutual diffusion coefficients of multicomponent mixtures is investigated, and a generalized correction term is derived. The generalized finite-size correction term was validated for the ternary molecular mixture chloroform/acetone/methanol as well as 28 ternary LJ systems. It is shown that only the diagonal elements of the Fick matrix show system-size dependency. The finite-size effects of these elements can be corrected by adding the term derived by Yeh and Hummer ( , , 15873-15879). By performing an eigenvalue analysis of the finite-size effects of the matrix of Fick diffusivities we show that the eigenvector matrix of Fick diffusivities does not depend on the size of the simulation box. Only eigenvalues, which describe the speed of diffusion, depend on the size of the system. An analytic relation for finite-size effects of the matrix of Maxwell-Stefan diffusivities was developed. All Maxwell-Stefan diffusivities depend on the system size, and the required correction depends on the matrix of thermodynamic factors.
研究了多组分混合物计算互扩散系数的系统尺寸依赖性，并推导了一个广义校正项。该广义有限尺寸校正项在三元分子混合物氯仿/丙酮/甲醇以及28个三元Lennard-Jones（LJ）系统中得到验证。结果表明，只有菲克矩阵的对角元素表现出系统尺寸依赖性。这些元素的有限尺寸效应可以通过添加Yeh和Hummer推导的项（，，15873 - 15879）来校正。通过对菲克扩散率矩阵的有限尺寸效应进行特征值分析，我们表明菲克扩散率的特征向量矩阵不依赖于模拟盒的大小。只有描述扩散速度的特征值依赖于系统的大小。推导了麦克斯韦-斯蒂芬扩散率矩阵有限尺寸效应的解析关系。所有麦克斯韦-斯蒂芬扩散率都依赖于系统大小，所需的校正依赖于热力学因子矩阵。
