Used for non-electrolyte concentrated solutions.
For ideal liquid mixtures of unassociated components A and B, Vignes recommended the following relationship: $$ D_{AB} = ({D_{AB}})^{X_B}({D_{BA}})^{X_A} $$
Where $$D_{AB}$$ is the diffusion coefficient of A in B at infinite dilution, $$D_{BA}$$ is the diffusion coefficient of B in A at infinite dilution, and $$X_A$$ and $$ X_B$$ the mole fractions of components A and B, respectively.