[gmx-users] Fatal error: moleculetype DPC is redefined.

[Mark Abraham]

mario ciappy wrote:
> Hello everyone,
> when I try to minimise peptide-DPC system with grompp command, I find 
> the error
> 
> "Program grompp, VERSION 3.3.1
> Source code file: toppush.c, line: 891

Curiously enough, the error message:

> Fatal error:
> moleculetype DPC is redefined.

means that your .top file is defining the DPC molecule more than once.

> I produced the dpc.itp file with dundee server.

That's probably fine, but either that file is being #included more than 
once, or you are #including two files that do that, or similar. Look 
carefully for that. If you get desperate, use "cpp -I$GMXLIB file.top 
file_after_cpp.top" (which is effectively what grompp is doing) and 
search for DPC.

Mark