[gmx-developers] Problem with dihedral restraint in gromacs 4.6

[Bogdan Costescu]

On Mon, Feb 11, 2013 at 11:51 AM, Landry Charlier
<landry.charlier at univ-montp1.fr> wrote:
> Incorrect number of parameters - found 2, expected 3 or 6 for Dih. Rest..
> ...
> grompp waits a third parameter but the manual p 133 says that only 2
> parameters (phi & dphi) are required.

The code expects indeed 3 (or 6 for free energy calculations)
parameters. They are phi, dphi and kfac. You can look at the code in
src/gmxlib/bondfree.c::dihres() for how they are used.

Cheers,
Bogdan