I'm studying a polymer water system. I want to use pcff FF on the polymer, and TIP3P or SPC/E for water. I know how to apply pcff on both, but what if I want to use different force fileds for those? Specially, I don't know how to use TIP3P for water molecules. Isn't .frc files availbale for water models?

Finally, I need to export the whole result of the system to a data file for lammps.