[gmx-users] unknown cmap torsion between atoms

[Mark Abraham]

On 1/11/2011 1:24 PM, ram bio wrote:
> Dear Gromacs users,
>
> I have built a protein embedded in popc bilayer and executed pdb2gmx 
> using charmm27 ff on the system and the toplogy file was created 
> without errors, but when wanted to minimise the system with grompp i 
> am getting an error as : unknown cmap torsion between atoms 8377 8379 
> 8381 8394 8397.
>
> Could someone please explain me what this error mean and how to 
> overcome this.

It means you are somehow using CMAP on a dihedral whose atom types do 
not have a known CMAP function - "unknown CMAP torsion". You need to do 
some detective work on those atoms and their types to work out why.

Mark