Hessian biased force field for polysilane polymers

We report a force field (FF) suitable for molecular dynamics simulations of polysilane polymers. This FF, denoted MSXX, was developed using the Hessian biased method to describe accurately the vibrational states, the ab initio torsional potential energy surface, and the ab initio electrostatic charges of polysilane oligomers. This MSXX FF was used to calculate various spectroscopic and mechanical properties of the polysilane crystal. Stress-strain curves and surface energies are reported. Gibbs molecular dynamics calculations (Nosè, Rahman-Parrinello) were used to predict various materials properties at higher temperatures. Phonon dispersion curves and elastic constants were calculated at various temperatures. Although this polymer is of increasing industrial interest, we could find no experimental data with which to compare these predictions.