A force field has been developed for Li(2)SiF(6) for subsequent use in Molecular Dynamics (MD) simulations involving Li(+) and SiF(2-) (6) ions in a polymer electrolyte host. Both ab initio calculations and available empirical data have been used. The force field has been verified in simulations of the crystal structure of Li(2)SiF(6) in two different space groups: P321 and P3(-)m1. The use of MD simulation to assess the correct space group for Li(2)SiF(6) shows that it is probably P321.