Prediction of polymer crystal structures and properties: a method utilizing simultaneous inter- and intramolecular energy minimization

A method is described for using molecular mechanics to calculate in a unified manner, from transferable conformational energy functions, the packing parameters and energy, vibrational dispersion curves, heat capacity and thermodynamic functions, elastic constants, and refractive indices of polymer crystals. The inter- and intramolecular conformational energies are simultaneously minimized. This allows assessment of the effect of packing forces on the polymer helix parameters and the intramolecular geometry. In addition, the converged Newton--Raphson coefficient matrix used in minimization allows convenient vibrational analysis and calculation of the elastic constants of the crystal. 18 ref.--AA