Molecular Dynamics Simulation of Model Solution: Calculation of Diffusion Coefficients

Molecular dynamics simulations have been used to determine the radial distribution functions, the self diffusion coefficients D 1 , D 2 and the mutual diffusion coefficient D 12 of model solutions. The diffusion coefficients were calculated both from the Green Kubo integrals from the velocity correlation function and from the Einstein relations for the mean square displacement. Good agreements were obtained between the both sets of the diffusion cofficients, respectively, from the two methods. It was also shown that the mutual diffusion coefficient D 12 can be accurately related to the self diffusion coefficients of D 1 and D 2 by D 12 = x 1D 1+x 2D 2 .