Parmchk creates force field modification (frcmod) files that fill in missing parameters. The following command creates a frcmod file from the previously created mol2 file:

Repeat this step for the two remaining mol2 files. You can get the frcmod files we created here: frcmod.acn, frcmod.bmi, and frcmod.bf4. Compare them to the ones you have created. Note that the frcmod.acn file is essentially empty, since all of the parameters needed for that molecule were present in the gaff.dat file. You can get rid of this file if you want.