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ffG43a1  GROMOS96 43a1 Forcefield (official distribution)
ffG43b1  GROMOS96 43b1 Vacuum Forcefield (official distribution)
ffG43a2  GROMOS96 43a2 Forcefield (development) (improved alkane dihedrals)
ffoplsaa OPLS-AA/L all-atom force field (2001 aminoacid dihedrals)
ffgmx    Gromacs Forcefield (see manual)
ffgmx2   gmx Forcefield with hydrogens for NMR stuff (Do NOT use for new runs)