[gmx-users] about PME

[David]

On Fri, 2003-01-17 at 17:42, Alan Wilter Sousa da Silva wrote:
> Thank you Dr. der Spoel.
> 
> I checked darden93 and I wasn't able to find a clear answer like you gave
> me.
> 
> On 17 Jan 2003, David van der Spoel wrote:
> 
> > > 	I'm just trying to wonder how PME works.  The procedure of
> > > assigning charges to the interpolated grid is done at every step of MD,
> > > isn't it?
> > >
> > yes.
Directly answering your question: yes we have to redo the charge
assignment every step because the particles move. Some groups use a
scheme in which PME is only done every nth step, but that gives
considerable errors because the short range Coulomb is modified as well.


-- 
Groeten, David.
________________________________________________________________________
Dr. David van der Spoel, 	Dept. of Cell and Molecular Biology
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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