[gmx-users] TIP5P and cg minimization

[Mark Abraham]

>
> Hi list,
> I have solvated my protein in TIP5P box that's provided by 3.3.3. However,
> when I try to run an energy minimization using cg (at the grompp stage), I
> get:
> ERROR: can not do Conjugate Gradients with constraints (218328)
>
> I don't have any problem using the same em.mdp file on TIP4P, so I figured
> it has something to do with TIP5P. Steep descent works, but it bugs me
> that cg wouldn't work. As far as I can tell, there's no constraints in my
> em.mdp file and my *.top (*.itp files too). Has anybody else encounter the
> same problem? Thank you in advance.

[ settles ] are constraints. Check for them.

Mark