https://doi.org/10.1351/goldbook.S05502
In an assembly of macromolecules, a continuous distribution with the differential @M03716@ of the form: \[f_{\text{w}}(x)\ \text{d}x = \frac{a^{b\,+\,1}}{\varGamma\left(b\,+\,1\right)}\ x^{b}\ \text{e}^{-a\ x}\ \text{d}x\] where \(x\) is a parameter characterizing the @C00956@, such as @R05271@ or @D01569@, \(a\) and \(b\) are positive adjustable parameters, and (\(\mathit{\Gamma}\left(b+1\right)\)) is the gamma function of (\(b+1\)).