[gmx-users] grompp error - incorrect number of parameters

[Mark Abraham]

On 17/05/2012 11:47 PM, Lara Bunte wrote:
> Hello
>
>
> After
>
>
> grompp -f em.mdp -p topol.top -c solvated.gro -o em.tpr
>
>
> I got the error:
>
> Incorrect number of parameters - found 2, expected 4 or 4 for U-B.
>
>
> I thought that this could be an inconsistency be declaring the functions, but in my topology I have function 4 (for improper dihedrals):
>
>
> Out of topol.top
>
> [ dihedrals ]
> ;  ai    aj    ak    al funct            c0            c1            c2            c3
>      1     8     6     4     4    180   100
>
>
> And in my .rtp file in the CHARMM27 force field folder I have:
>
> Out of .rtp file
> ; bonds  angles  dihedrals  impropers
>       1       5          4        4

There's no aminoacids.rtp file for CHARMM27 that has ever looked like 
this. Any that did is not CHARMM27.

Mark

>
>
> and in my ffbonded.itp file I have:
> [ dihedraltypes ]
> ; i     j       k       l       func    q0      cq
> ON1     NN3A      CN1A       NN2U   4   180   100
>
>
> So in alle three files, ffbonded.itp, topol.top and the .rtp parametrization file I have the function 4 for the improper dihedrals.
>
>
> What is the problem?
>
> Thanks for helping me
> Greetings
> Lara