https://doi.org/10.1351/goldbook.S05582
The @D01719@ \(D_{i}^{*}\) of species \(i\) in the absence of a @C01032@ @G02669@. It is related to the @D01719@ \(D_{i}\) by \[D_{i}^{*}=D_{i}\ \frac{\partial (\ln c_{i})}{\partial \ln a_{i}}\] where \(a_{i}\) is the activity of \(i\) in the solution, and \(c_{i}\) is the concentration of \(i\). If an @I03336@ species (\(i^{*}\)) is used to study @D01716@, the @T06422@ @D01719@, \(D_{i}^{*}\), is practically identical to the self-@D01719@ provided that the @I03327@ is sufficiently small.