Also contains definition of: logarithmic distribution coefficient in precipitation

https://doi.org/10.1351/goldbook.L03487

During the formation of a mixed crystal from a solution containing two components 'A' and 'B', the latter may be distributed according to the equation \[K_{\text{A},\text{B}}=\frac{b\ (a_{0}- a)}{a\ (b_{0}- b)}\] In this homogeneous distribution, a0 and b0 are the respective concentrations in the solution before crystallization and a and b are the respective concentrations in the solution after crystallization. KA,B is usually called the separation factor. The term homogeneous distribution coefficient is not recommended. Alternatively the distribution of the micro-component may follow the equation of Doerner and Hoskins \[\ln (\frac{a_{0}}{a}) = \lambda \ \ln (\frac{b_{0}}{b})\] (logarithmic distribution) where λ is usually called the logarithmic distribution coefficient, the meaning of the other symbols remaining the same. Exactly homogeneous or logarithmic distributions are extreme cases and very seldom encountered.*Source: *

Orange Book, 2^{nd} ed., p. 85 (http://media.iupac.org/publications/analytical_compendium/)

Orange Book, 2