 Freely rotating chain

A freely rotating chain has fixed bond length and fixed angle between successive forward bond vectors, with independently uniform torsion angles. It neglects interactions between distant chain segments. The fixed angle introduces short-range orientational correlations even though the torsional rotations are unrestricted. Its characteristic ratio of a freely rotating chain converts those correlations into an end-to-end size; its equivalent long-chain link is the Kuhn length of a freely rotating chain.