Hello everyone,
I had a force field for my ligand in Amber format. By using acpype i converted it to GROMACS. But the atom types in the topology file are still GAFF-like (those lowercase atom types):
; nr type resi res atom cgnr charge mass ; qtot bond_type
1 na 1 CHL N 1 -0.638039 14.01000 ; qtot -0.638
2 cc 1 CHL C 2 0.193729 12.01000 ; qtot -0.444
3 cc 1 CHL C1 3 -0.043093 12.01000 ; qtot -0.487
4 cd 1 CHL C2 4 0.053345 12.01000 ; qtot -0.434
5 c3 1 CHL C3 5 -0.304092 12.01000 ; qtot -0.738
6 hc 1 CHL H 6 0.093053 1.00800 ; qtot -0.645
Gromacs does not accept this. Do you know how to modify this topology file? Thank you