[gmx-users] comparison of reaction field and PME

[David van der Spoel]

On Mon, 4 Mar 2002, Yuguang Mu wrote:

>I have a little experience of AMBER package, there using PME
>a little slower that CUT-OFF.

But in both cases, gromacs is considerably faster. The difference in speed 
is due to the more complex innerloop. Also, you can reduce the cut-off for 
Coulomb when using PME (e.g. to 0.9) while you keep the LJ at 1.2. This 
will give you the same Coulomb forces as when using 1.2, but much faster.
The LJ forces between 0.9 and 1.2 are only updated when you do 
neighboursearching (recommend nstlist = 5).

Groeten, David.
________________________________________________________________________
Dr. David van der Spoel, 	Biomedical center, Dept. of Biochemistry
Husargatan 3, Box 576,  	75123 Uppsala, Sweden
phone:	46 18 471 4205		fax: 46 18 511 755
spoel at xray.bmc.uu.se	spoel at gromacs.org   http://zorn.bmc.uu.se/~spoel
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