NEW ORIENTATIONALLY ORDERED PHASES OF A HOMOPOLYMER

We present results of Monte Carlo simulations of a homopolymer with th ree-body interactions on a lattice. At equilibrium we find three colla psed phases with different orientational order. The first one may be d escribed as a conventional phase with effective three-body attraction. Two other phases are observed in the region of the phase diagram corr esponding to three-body repulsion. The second phase is characterized b y local orientational order within the globule. The third one possesse s global orientational order and it appears to be analogous to nematic phase of a liquid crystal. Kinetics of the collapse transition to the phase III is crucially different from that of phase I and II due to f ormation of clusters with different orientations at the intermediate s tage. This is the origin of a metastable long-lived state in kinetics. (C) 1996 American Institute of Physics.