https://doi.org/10.1351/goldbook.R05405
The square root of the mean-square end-to-end distance of a segments each of length , it is given by: The subscript zero is used to indicate unperturbed dimensions, as in . If this term is used repeatedly, and if it is not confusing, the abbreviated name 'end-to-end distance' may be used.
linear polymer
chain averaged over all conformations of the chain. For a freely jointed chain consisting of