Numerical calculation of the melting phase diagram of low molecular-weight polyethylene

Using thermodynamic integration, we calculate free energies of the melt and the crystalline phases of a model system of C₁₉₈H₃₉₈ with a realistic all-atom potential. We use the Gibbs-Duhem integration scheme to calculate the melting curve over the experimentally relevant pressure range. The crystal structure and the melting curve obtained from our simulation are in good quantitative agreement with the available experimental results.