[gmx-users] about PME
spoel at xray.bmc.uu.se
Fri Jan 17 19:10:57 CET 2003
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
> 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.
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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