## Wikipedia - Efekty steryczne 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]