[gmx-users] dihedral restraints -- works, but restraint energy 0.000

[David Mobley]

I'm still trying to implement dihedral restraints. My problem is
essentially the same as the one described in this previous message
(http://www.gromacs.org/pipermail/gmx-users/2004-February/009536.html).
I put dihedral restraints in my topology file, for example, like:

[ dihedral_restraints ]
; ai    aj     ak     al   type label  phi   dphi   kfac  power
17     19     26     27    1   0    80.0   0.0    1.0  2.0

and add:

dihre = simple, 
dihre_fc = 1000, 
dihre_tau =0.0 and 
nstdihreout =10. 

for example, to my mdp file. grompp works fine and mdrun prints out
information about the restraints -- but the dihedral restraint energy
is always zero in the output.

Any suggestions?

I am using the CVS version from Nov. 04 because I need to do free
energy calculations while having dihedral restraints turned on. The
version I am using is mentioned here:
http://www.gromacs.org/pipermail/gmx-developers/2005-February/001022.html.

Thanks,
David