[CP2K:652] Re: cp2k speedup on multicore machines
teodor... at gmail.com
Wed Jan 30 11:31:55 UTC 2008
as we said already on a similar topic in this mailing list, there are
few things that can speed-up
the SCF during an MD.
I will repeat them here hoping that these suggestion will help also
The most fundamental one is a good extrapolator and a good
preconditioner for the SCF.
instead of those used in that tests you run you may want to try:
and in &OT
Of course the choice of the preconditioner is very dependent from the
system you're running. But as a preliminar
trial this should be ok.
Moreover every time OT is used to optimize the wavefunction it is
HIGLY suggested to use a nested SCF procedure..
This does not help at all normal diagonalization schemes but improves
terribly the convergence with OT.
This is the way to go:
Don't use too many steps for the inner SCF levels (in the range 30-40
should be ok) and quite few for the outer (5-10)..
Try it and you will see a great improvement for the first SCF
Keep in mind that absolute running time depends on many things..
CUTOFF, basis set, preconditioner, extrapolation,
threshold for the convergence of the SCF, precision required in the
integration and collocation of the density and so on..
So a full comparison can be done only with the exactly the same input
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