Normal modes and their dispersion in poly(α-isobutyl, β-l-aspartate): II. 13/4 Helix

Poly(α-isobutyl, β-l-aspartate) is a polymer which belongs to a family of synthetic and polypeptide derivatives. It exhibit polymorphism and exist in hexagonal (13/4 helix) as well as tetragonal form (4/1 helix). Both helices are stable in different environment. A normal mode analysis and their dispersion shows several interesting features including Von Hove type singularities and repulsion as a result of internal symmetry. Predictive heat capacity as a function of temperature via density-of-states is being reported.