[gpaw-users] Computational cost of vdW-DF
Jens Jørgen Mortensen
jensj at fysik.dtu.dk
Tue Apr 12 16:15:18 CEST 2011
On Tue, 2011-04-12 at 15:29 +0200, Duy Le wrote:
> 2011/4/12 Jens Jørgen Mortensen <jensj at fysik.dtu.dk>:
> > On Mon, 2011-04-11 at 23:56 +0200, Duy Le wrote:
> >> Dear all,
> >> As I understand, the approach of Román-Pérez and Soler (PRL 2009) has
> >> been implemented in GPAW. I wonder why the self-consistent vdW-DF
> >> calculation is still extremely expensive (3 or 4 times in most of my
> >> calculations) in comparison to regular GGA-PBE calculation.
> >> Does any of you experience this slowness? I would like to know the reason.
> >
> > For a small system with few electrons, the calculation of the vdW-DF
> > potential will dominate. With more electrons the vdW-DF part should
> > become smaller unless you run on so many cores that the parallelization
> > of the vdW-DF stuff stops scaling. So, what is your system and how many
> > cpu's do you use?
> It is the case, my systems are big, in the order of about 70-150
> atoms. Of course I have to use lot of cores (64 to 512 cores in most
> of the case) otherwise I don't have enough memory allocated.
> Is there any way to improve it? The PBE calculation is scaled very well.
The current implementation of the vdW-DF xc-potential scales only up to
20 cores. Could you show us the text output from one of your
calculations - you should be able to see the timings for the different
parts of the calculation in the text output.
Jens Jørgen
> > Jens Jørgen
> >
>
> --------------------------------------------------
> Duy Le
> PhD Student
> Department of Physics
> University of Central Florida.
>
> "Men don't need hand to do things"
> >> Thank you.
> >> --------------------------------------------------
> >> Duy Le
> >> PhD Student
> >> Department of Physics
> >> University of Central Florida.
> >>
> >> "Men don't need hand to do things"
> >>
> >> _______________________________________________
> >> gpaw-users mailing list
> >> gpaw-users at listserv.fysik.dtu.dk
> >> https://listserv.fysik.dtu.dk/mailman/listinfo/gpaw-users
> >
> >
More information about the gpaw-users
mailing list