Theory of the crystallisation of hard polymeric chains in an orienting field

We apply a recently proposed density functional theory (DFT) for hard polymeric chains to study the influence of a quadrupolar orienting field on the freezing of model polymers. We find that a "disorienting" field, mimicking elongational flow, promotes crystallization, while an "orienting" field, which corresponds to longitudinal shear flow, destabilizes the crystal phase. We also investigate the relative stability of two close-packed crystal lattice types, face-centered cubic and hexagonal close-packed. Geometrical effects, such as the orientation of the field with respect to the main axes of the crystal, play an important role in stabilizing one crystal type over another.