Re: NAMD 2.7b1: metadynamics+tclForces => "... design error, GlobalMasterServer..."

From: Giacomo Fiorin (
Date: Thu May 14 2009 - 19:23:19 CDT

Hi Sebastian, more than a bug it seems that the code prevents the
occurrence of a bug by forbidding you from running together two
instances of a "global forces" method (Tcl, metadynamics, TMD...).
Unless they are defined on the very same set of atoms. Perhaps
someone more familiar with the GlobalMaster internal architecture can
help better.

In case running tcl and metadynamics together turned out not to be
possible, there may be a chance that you can apply the tcl restraints
on several "dihedral" collective variables (i.e. in parallel to
metadynamics, but on the same configuration file). You can apply
either a harmonic restraint to each one, or a biasing function of your
choice mapped on a grid, by feeding it to several instances of ABF and
telling each of these instances to not refine it as if it was a PMF.


---- ----
 Giacomo Fiorin
   Center for Molecular Modeling at
     University of Pennsylvania
     231 S 34th Street, Philadelphia, PA 19104-6323
 phone: (+1)-215-573-4773
 fax: (+1)-215-573-6233
 mobile: (+1)-267-324-7676
 mail: giacomo.fiorin_<at>
---- ----

On Thu, May 14, 2009 at 5:41 PM, Sebastian Stolzenberg
<> wrote:
> Dear All,
> I successfully used metadynamics with tclForces in a serial NAMD2.7b1 run.
> In parallel, however, I get the following error message:
> ..
> TCL: Running for 5000000 steps
> FATAL ERROR: Due to a design error, GlobalMasterServer does not support
> individual atom requests from multiple global force clients on parallel
> runs.
> ..
> Running either metadynamics or tclForces in parallel, however, works fine.
> Is this a bug?
> Please let me know, if you need my scripts.
> Cheers,
> Sebastian

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