title: Structure and cohesive energy of dipolar helices.
abstract: This paper deals with the investigation of cohesive energy in dipolar helices made up of hard spheres. Such tubular helical structures are ubiquitous objects in biological systems. We observe a complex dependence of cohesive energy on surface packing fraction and dipole moment distribution. As far as single helices are concerned, the lowest cohesive energy is achieved at the highest surface packing fraction. Besides, a striking non-monotonic behavior is reported for the cohesive energy as a function of the surface packing fraction. For multiple helices, we discover a new phase, exhibiting markedly higher cohesive energy. This phase is referred to as ZZ tube consisting of stacked crown rings (reminiscent of a pile of zig-zag rings), resulting in a local triangular arrangement with densely packed filaments parallel to the tube axis.
authors.affiliation: Scientific Computing Laboratory, Institute of Physics Belgrade, University of Belgrade, Pregrevica 118, 11080 Belgrade, Serbia. igor.stankovic@ipb.ac.rs.
authors.forename: Igor
authors.initials: I
authors.lastname: Stanković
authors.affiliation: Scientific Computing Laboratory, Institute of Physics Belgrade, University of Belgrade, Pregrevica 118, 11080 Belgrade, Serbia. igor.stankovic@ipb.ac.rs.
authors.forename: Miljan
authors.initials: M
authors.lastname: Dašić
authors.affiliation: Institut de Chimie, Physique et Matériaux (ICPM), Université de Lorraine, 1 Bd. Arago, 57070 Metz, France.
authors.forename: René
authors.initials: R
authors.lastname: Messina
mesh_terms: D004247:DNA / Q000737:chemistry; D008958:Models, Molecular; D011506:Proteins / Q000737:chemistry; D011789:Quantum Theory; D013816:Thermodynamics
chemical_list: D011506:Proteins; D004247:DNA