[gmx-users] Difference between the electrostatic treatments PME/Cut-offs and Reaction Field

[Mark Abraham]

Things should be identical - any quantity computed from a zero charge has
to be zero :-).

Mark

On Thu, May 30, 2013 at 1:26 PM, Dr. Vitaly Chaban <vvchaban at gmail.com>wrote:

> Hmmm...
>
> And what does the observed difference look like, numerically?
>
>
>
>
>
> On Thu, May 30, 2013 at 10:14 AM, Mark Abraham <mark.j.abraham at gmail.com
> >wrote:
>
> > No charges = no problem. You can trivially test this yourself with mdrun
> > -rerun ;-)  Manual 4.1.4 talks about what RF is doing.
> >
> > Mark
> >
> >
> > On Thu, May 30, 2013 at 6:38 AM, Dallas Warren <Dallas.Warren at monash.edu
> > >wrote:
> >
> > > In a system that has no charges, should we observe a difference between
> > > simulations using PME/Cut-offs or Reaction Field?
> > >
> > > >From my understanding there should not be, since there are no charges
> > > which treatment you use shouldn't' make a difference.
> > >
> > > However, it does and I am trying to work out why.
> > >
> > > Any suggestions on the reason?
> > >
> > > What is it that Reaction Field is doing, does it influence anything
> other
> > > than long range charge interactions?
> > >
> > > Catch ya,
> > >
> > > Dr. Dallas Warren
> > > Drug Discovery Biology
> > > Monash Institute of Pharmaceutical Sciences, Monash University
> > > 381 Royal Parade, Parkville VIC 3052
> > > dallas.warren at monash.edu
> > > +61 3 9903 9304
> > > ---------------------------------
> > > When the only tool you own is a hammer, every problem begins to
> resemble
> > a
> > > nail.
> > > --
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