Molecular dynamics simulation was applied to a study of the diffusion properties in binary liquid mixtures made up of soft-sphere particles with different sizes and masses. Self- and distinct velocity correlation functions and related diffusion coefficients were calculated. Special attention was paid to the dynamic cross correlations which were computed using relative mean molecular velocity correlation functions which were independent of the reference frame. The differences between the distinct velocity correlations and diffusion coefficients in various reference frames (mass-fixed, number-fixed, and solvent-fixed) were considered.

Self- and Cross-Velocity Correlation Functions and Diffusion Coefficients in Liquids: a Molecular Dynamics Study of Binary Mixtures of Soft Spheres. Trullàs, J., Padró, J.A.: Physical Review E, 1994, 50[2], 1162-70