Density of States for a Short Overlapping-Bead Polymer: Clues to a Mechanism for Helix Formation?

TL;DR

This study investigates the density of states in short overlapping-bead polymers, revealing features like magic numbers and bimodal energy distributions that may elucidate helix formation mechanisms.

Contribution

It introduces a model for short polymers that exhibits key behaviors linked to helix formation, including discontinuities and bimodal energy distributions.

Findings

Identification of magic numbers of overlap parameter

Discontinuous derivatives of densities of states

Bimodal energy probability distributions

Abstract

The densities of states are evaluated for very short chain molecules made up of overlapping monomers, using a model which has previously been shown to produce helical structure. The results of numerical calculations are presented for tetramers and pentamers. We show that these models demonstrate behaviors relevant to the behaviors seen in longer, helix forming chains, particularly, "magic numbers" of the overlap parameter where the derivatives of the densities of states change discontinuously, and a region of bimodal energy probability distributions, reminiscent of a first order phase transition in a bulk system.