Error in generating OPLS-AA for deprotonated PFBS ( [F3C-(CF2)3-SO3]- )

[Smile098]

• [√] I believe this to be a bug with LigParGen
• This is a feature request

Issue Information

Software name & Version : LigParGen online Generator at http://zarbi.chem.yale.edu/ligpargen/
Method: PDB input files generated by Material Studio

Expected Behavior

I built PFBS (F3C-(CF2)3-SO3H) and deprotonated PFBS ([F3C-(CF2)3-SO3]-) molecular models in Material Studio and exported as PDB files, trying to obtain the OPLS-AA parameters for them using LigParGen.
Default options were used for PFBS (F3C-(CF2)3-SO3H).
molecular charge was set to -1 for deprotonated PFBS ([F3C-(CF2)3-SO3]-).

Actual Behavior

OPLS-AA parameters was successfully generated for PFBS, but got error for deprotonated PFBS ([F3C-(CF2)3-SO3]-).
I set molecular charge to -1, but still got the error message Found residue ligand MOL

I don't know whether the force field parameters and atom charges are the same between PFBS and deprotonated PFBS.

Here is my PDB files,
PFBS.pdb.txt
PFBS_H.pdb.txt

Thank you so much in advance~