[gmx-users] Problem with topology generation by Amber 12 ff

[Amir Zeb]

Hello gmx users,

I have generated topology and coordinate files of ZN metalloprotein by
Amber 12 ff. Now I am facing this following issue at grompp run:

"ERROR 1 [file topol_Protein_chain_A.itp, line 49741]:
  No default Improper Dih. types"

If I use another ff like Amber99SB- ILDN, there is no such error. I
searched out the solution on google but could not find the answer.

Please help me how to fix this issue?

Thanks in advance!