AbstractThe Rayleigh ratio has been obtained for the following mixtures of non‐electrolytes that show “w‐shape” CEpvs.xcurves: Nitrobenzene + n‐Heptane, 1,4‐Dichlorobutane + n‐Heptane and Acetone + n‐Dodecane. From them, the concentration‐concentration correlation functionScc(0) has been calculated, as well as the excess Gibbs energy. It has been found that a clear tendency to homocoordination is present in all the mixtures studied. There is a rough correspondence between the concentration at which the maximum of theScc(0) curves occur and those at which the negative curvature regions exist in the CEpcurves. Also the larger the value of max.Scc(0) the more intense the “w‐shape” effect. Despite size differences between the components and specific interactions which complicate the connection betweenScc(0) and CEp, an analysis in terms of simple mean field models supports the view that the systems which show “w‐shape” CEpcurves still feel the effects of the more or less distant UCST. HenceScc(0) is proposed as an i