[gmx-users] pull=constraint gives zero forces
schlesi at uni-mainz.de
Tue Oct 9 11:20:10 CEST 2012
But for GMX 4.0.7 there are forces in the pullf.xvg. The forces which
arise rom the contraint the hold the two groups fixed. I use them for
I use the following mdp-parameters, probably this gives you an idea what
you might make different:
; AFM OPTIONS
pull = constraint
pull_geometry = distance
pull_dim = Y Y Y
pull_start = yes
pull_nstfout = 10
pull_nstxout = 500000
pull_ngroups = 1
pull_group0 = REF
pull_group1 = ZUG
pull_rate1 = 0.000
pull_init1 = 0.000
pull_constr_tol = 1e-06
But as Chris said, better post the complete mdp-file (probably for both
GMX 4.0.7 and 4.5.x) so we can comment on them.
Am 09.10.2012 04:00, schrieb gmx-users-request at gromacs.org:
> Please post your entire .mdp file and a snip of the output in your pullf and pullc files.
> (Your initial post on this topic was also missing these, although the text reads as if you intended to include them).
> I'll note that there are no forces when using constraints, so the fact that you get zero forces for a constrained run
> is not really surprising. I guess the thing is that it doesn't work to keep atoms in place for you,
> which we can help you with if you post more details.
> -- original message --
> Following up on this post. I've tried the same runs using version 4.0.7,
> which gave immediate segmentation faults. Not sure if this is a clue or a
> trivial consequence of switching versions, but there it is.
> Any other ideas why the pullf output just contains zeros?
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