Ab initio calculations and force field development for computer simulation of polysilanes

An all-atom force field for computer simulation of polysilanes, including their alkyl and phenyl side-chain derivatives, is developed based on ab initio calculations and liquid-state simulations of simple silane molecules. Validation of the force field shows good agreement with experimental data of isolated and condensed silanes and polysilanes. Conformational structures and energies of polysilane and poly(dimethylsilane) were studied based on ab initio calculations and the force field developed. It is found that the all-trans backbone of isolated polysilane is more stable than the gauche. Poly(dimethylsilane) has a helical backbone in the gas phase but is all-trans in the crystal due to the interchain nonbonded interaction