[gmx-developers] dispersion correction / exploding box

[David]

On Mon, 2005-08-22 at 18:42 +0200, Rainer Böckmann wrote:
> Dear All:
> 
> we experienced a very fast (~10-50ps) increasing/exploding box for a 
> system of approx. 100,000 atoms using the OPLS forcefield, TIP4 water, 
> and a dodecahedron box aready during position restraint runs (restraints 
> on the protein). Further options:
> 
> gromacs 3.3, cvs version (download ~3 weeks ago)
> PME
> energy/pressure dispersion correction switched on
> 310 K, 1bar
> 
> We observe this behaviour only for certain box sizes/proteins, e.g. the 
> box explodes using a distance of 1.4nm or 1.5nm  between the protein and 
> the box but not for 1.2nm. It is not dependent on the PME parameters, 
> but at least partly on the dispersion correction term. The box appears 
> to be stable without the dispersion correction.'

Can you give more details? Dispersion energy, VDW treatment and cut-offs etc.

> 
> Any ideas?
> 
> Thanks & best wishes,
> Rainer
> 
-- 
David.
________________________________________________________________________
David van der Spoel, PhD, Assoc. Prof., Molecular Biophysics group,
Dept. of Cell and Molecular Biology, Uppsala University.
Husargatan 3, Box 596,          75124 Uppsala, Sweden
phone:  46 18 471 4205          fax: 46 18 511 755
spoel at xray.bmc.uu.se    spoel at gromacs.org   http://xray.bmc.uu.se/~spoel
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