Condensed states of a semiflexible homopolymer: ordered globules and toroids

We examine the condensed states for a semiflexible polymer in poor solvent as a function of stiffness, focusing on the transition region between globule and torus. Conservative estimates for the upper and lower bounds to the globule–torus transition region are found. These are then used to demonstrate that the polymer globule undergoes considerable changes to its overall morphology and internal packing arrangements for stiffness values outside this transition region. Using a variety of methods we characterize these globular structures as stiffness is varied.