[gpaw-users] vdw that memory intensive?

[Sampsa Riikonen]

Dear List,

I have the following problem when trying to calculate a big water/ice 
clusters using the vdw functional.

When trying to use the vdw module (commented lines correspond to older 
version of gpaw) ..
---------
# from gpaw.vdw import FFTVDWFunctional #  gpaw < 0.8
from gpaw.xc.vdw import FFTVDWFunctional # gpaw 0.8
# vdw = FFTVDWFunctional(nspins=1, verbose=True) # gpaw < 0.8
vdw = FFTVDWFunctional() # gpaw 0.8
calc.set(xc=vdw)
--------
.. with a 20 water molecule cluster running on 16 prosessors each one of 
them having 4.5 gb of
memory reserved, gpaw dies because it goes out of memory..! (Cray 
XT4/XT5, computer node linux: "OOM killer").

Has anyone experienced a similar problem..?

_Without vdw_ that system runs ok.

_With vdw_ for a single water molecule it also works ok.

Regards,

Sampsa