Comparisons between coupling model and molecular dynamics simulation for local chain motions in bulk amorphous polymers

Recent molecular dynamics simulation of the local chain dynamics of bulk amorphous polymers by Takeuchi and Roe [J. Chem. Phys. 94, 7446 (1991)] have brought out many interesting features of various time-correlation functions of bond reorientational motion. It is pointed out here that these features are in good agreement with what is predicted by the coupling model for local chain motions of amorphous polymers, and furthermore these features are common to relaxations in a number of interacting many body systems.