ForceFieldConfigurator.assignAtomTypes assigns bad mmff94 atom type to NO2 N in CC(C)C(=O)Nc1ccc(c(c1)C(F)(F)F)N+[O-] molecule.
http://efficientbits.blogspot.co.uk/2015/08/mmff-partial-charges-improvements-in-cdk.html
http://efficientbits.blogspot.co.uk/2015/08/mmff-partial-charges-improvements-in-cdk.html