[gmx-users] CHARMM36 Termini Topology Incomplete

[João Rodrigues]

Hi all,

I am trying to setup a simulation of a peptide with neutral termini, using
the CHARMM36 port from the MacKerell lab. While pdb2gmx works well, grompp
fails with several erros about missing parameters, e.g.:

ERROR 1 [file topol.top, line 1225]:
  No default U-B types

...

ERROR 4 [file topol.top, line 1689]:
  No default Proper Dih. types

All these are related to the termini, whether I use CT2 or COOH, or NH2.
Could I copy the missing parameters from the old CHARMM27.ff files? Or
should I contact the developers directly? The default charged termini work
fine.

Or should I add the ACE/NMA caps in f.e. Pymol?

Cheers,

João