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, $a_0$ and $b_0$ are the respective concentrations in the solution before crystallization and $a$ and $b$ are the respective concentrations in the solution after crystallization. $K_{\text{A},\text{B}}$ 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 $\lambda$ 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.