steric factor

in polymers
https://doi.org/10.1351/goldbook.S05999
The ratio, \(\sigma \), of the @R05405@ of a polymer chain with unperturbed dimensions, \(< r^{2} >_{0}^{1/2}\), to that of a @F02518@ with the same structure, \(< r^{2} >_{0,f}^{1/2}\), i.e. \(\sqrt{\frac{< r^{2} >_{0}}{< r^{2} >_{0,f}}}\), in the limit of infinite @C00956@. The @S05998@ reflects the effect of hindrance to free rotation.
Source:
Purple Book, 1st ed., p. 50 [Terms] [Book]