The Microscopic Description of Mutual Diffusion and Closely Related Transport Processes in Liquid Mixtures

Velocity cross‐correlation functions are discussed and their use in the analysis of inelastic neutron scattering experiments in fluid mixtures is described including both the coherent and incoherent spectra. The formal results given here permit a microscopical description of mutual diffusion and closely related transport processes. In the hydrodynamic limit the velocity cross‐correlation coefficients introduced by Hertz are related to the ω → 0, x → 0 limits of the distinct partial dynamic structure factors in the same way, as the self diffusion coefficients are related to the self partial dynamic structure factors. Some possible applications of neutron scattering experiments to study collective motions in liquid mixtures are discussed.