PS ff99SB, ff12SB and ff14SB, from what I know, use the same charge
derivation method...
> I have on my Linux server Amber16 and AmberTool16.
> I need to simulate by MD enzyme with deprotonated side
> residue oxygen atom (anionic OG atom) of catalytic Ser.
> The ff14SB force field used for the simulation
> has no parameters for such a case.