[gmx-users] Unknown error

[Mark Abraham]

Alif M Latif wrote:
> Dear GROMACS users,
> 
> I'm trying to do energy minimization on benzoic acid structure when I 
> got this error:
> 
>  creating statusfile for 1 node...
> 
> Back Off! I just backed up mdout.mdp to ./#mdout.mdp.3#
> checking input for internal consistency...
> calling /lib/cpp...
> processing topology...
> Generated 1232 of the 1431 non-bonded parameter combinations
> Cleaning up temporary file gromppX1d9K4
> -------------------------------------------------------
> Program grompp, VERSION 3.3
> Source code file: toputil.c, line: 61
> 
> Fatal error:
> Atomtype 'K' not found!
> -------------------------------------------------------
> 
> I modified the ffgmx2.rtp by including the benzoic acid properties there.
> Any solution or hint on the problem there? Thanks a lot.

The atom type K isn't defined for this forcefield, and you're trying to 
use it. Check out Chapter 5 of the manual.

Mark