That, embarrassingly enough, seems to have fixed it. Thanks!
Might I burden you with an additional question? I was under the
(apparently incorrect) impression that SHAKE/SETTLE is not valid when doing
a minimization (although I don't really know what is meant by that). Or at
least this is apparently the case with CHARMM (or so the documentation
says). I would suppose such an incompatibility would depend on the
minimization algorithm and the implementation of the constraint method
(projecting out forces vs resetting positions or something like that
right?). What clever way does AMBER use to avoid these troubles (although
I don't know specifically what they are)?
Brian
On Thu, Nov 3, 2011 at 1:52 PM, David A Case <case.biomaps.rutgers.edu>wrote:
> On Thu, Nov 03, 2011, Brian Radak wrote:
> >
> > I am doing preliminary minimizations on a relatively small solvated
> > system. When the system is built with TIP3P waters, the minimization
> > proceeds more or less as expected, but if I build the system with
> TIP4P-Ew
> > waters the electronic energy goes off to negative infinity (****
> > behavior).
>
> You don't appear to have SHAKE turned on. That is needed for any of the
> Jorgensen-style water models. Try setting ntc=2.
>
> ...dac
>
>
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>
--
================================ Current Address =======================
Brian Radak : BioMaPS
Institute for Quantitative Biology
PhD candidate - York Research Group : Rutgers, The State
University of New Jersey
University of Minnesota - Twin Cities : Wright-Rieman Hall 101
Graduate Program in Chemical Physics : 610 Taylor Road,
Department of Chemistry : Piscataway, NJ
08854-8066
radak004.umn.edu :
radakb.biomaps.rutgers.edu
====================================================================
Sorry for the multiple e-mail addresses, just use the institute appropriate
address.
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Received on Thu Nov 03 2011 - 11:30:07 PDT
