[gmx-users] angle restraints

David Mobley dmobley at gmail.com
Thu May 11 18:34:28 CEST 2006


What version of the code are you using? There was a bug in the angle
restraints code until 3.3.1 (or 3.3 cvs) which caused angle restraints
to turn off gradually as a function of lambda in free energy
calculations, if I remember correctly. (See bugzilla for details:

However, I'm not sure that relates to the problem you're describing,
but it probably does, depending on the version you are using.

What exactly are you changing in the free energy calculation? Are you
changing the angle restraint as a function of lambda? If so, which way
are you changing it? Decreasing or increasing restraints?


On 5/11/06, Maarten Wolf <maarten_wolf at yahoo.co.uk> wrote:
> Dear users,
> I have a small system with a number of small peptides. I want to
> constraint the angle between the N-term to C-term vectors of different
> peptides. This works well, but if I do a FEP calculation the dG/dl
> becomes smaller than zero at some point.
> I expected it to be at least allways greater than zero (zero in the
> limit that the restraint does not have to do anything), since a force
> has to be aplied to restraint the angles.
> Can anybody explain where I am going wrong?
> Thanks
> Maarten
> Send instant messages to your online friends http://uk.messenger.yahoo.com
> _______________________________________________
> gmx-users mailing list    gmx-users at gromacs.org
> http://www.gromacs.org/mailman/listinfo/gmx-users
> Please don't post (un)subscribe requests to the list. Use the
> www interface or send it to gmx-users-request at gromacs.org.
> Can't post? Read http://www.gromacs.org/mailing_lists/users.php

More information about the gromacs.org_gmx-users mailing list