The ratio,

, of the
root-mean-square end-to-end distance of a polymer chain with unperturbed dimensions,

,
to that of a
freely rotating chain
with the same structure,

,
i.e.

,
in the limit of infinite
chain length.
The
steric factor reflects the effect of hindrance to free rotation.
Source:
Cite as:
IUPAC. Compendium of Chemical Terminology, 2nd ed. (the "Gold Book"). Compiled by
A. D. McNaught and A. Wilkinson. Blackwell Scientific Publications, Oxford (1997).
XML on-line corrected version: http://goldbook.iupac.org (2006-) created by M. Nic,
J. Jirat, B. Kosata; updates compiled by A. Jenkins. ISBN 0-9678550-9-8.
https://doi.org/10.1351/goldbook.