title: Dense orientationally ordered states of a single semiflexible macromolecule: an expanded ensemble Monte Carlo simulation.
abstract: Using a coarse-grained model we perform a Monte Carlo simulation of the state behavior of an individual semiflexible macromolecule. Chains consisting of N = 256 and 512 monomer units have been investigated. A recently proposed enhanced sampling Monte Carlo technique for the bond fluctuation model in an expanded ensemble in four-dimensional coordinate space was applied. The algorithm allows one to accelerate the sampling of statistically independent three-dimensional conformations in a dense globular state. We found that the temperature of the intraglobular liquid-solid transition decreases with increasing chain stiffness. We have investigated the possible intraglobular orientationally ordered (i.e., liquid-crystalline) structures and obtained a diagram of states for chains consisting of N = 256 monomer units. This diagram contains regions of stability of coil, two spherical globules (liquid and solid), and rod-like globule conformations. Transitions between the globular states are rounded first-order ones since the states of liquid, solid, and cylinder-like globules do have different internal symmetry.
authors.affiliation: Physics Department, Moscow State University, Russia.
authors.forename: J A
authors.initials: JA
authors.lastname: Martemyanova
authors.forename: M R
authors.initials: MR
authors.lastname: Stukan
authors.forename: V A
authors.initials: VA
authors.lastname: Ivanov
authors.forename: M
authors.initials: M
authors.lastname: Müller
authors.forename: W
authors.initials: W
authors.lastname: Paul
authors.forename: K
authors.initials: K
authors.lastname: Binder