[gpaw-users] What to use spectral parallelization instead of over the kpoints when calculating the response function

[jun yan]

Dear Anders, 

    How many w frequency points do you use in your calculation ? For the non Hilbert transform calculation you use, its better to use either 1 frequency point, or use the number of frequency points that can be divided by the number of cores. 

All the best, 
Jun

On Nov 9, 2011, at 10:15 AM, Anders Hellman wrote:

> Dear GPAW-users,
> 
> I am trying to calculate the response function, however, I think I am hitting some memory limit and would like to parallelice over the spectral function. I introduce the kcommsize, but when ever the kcommsize is set to a number below the number of cores I get the following error massage;
> 
>  File "run.py", line 42, in ?
>    df.get_macroscopic_dielectric_constant()
>  File "/lap/gpaw/0.8.0.8092/lib64/python2.4/site-packages/gpaw/response/df.py", line 281, in get_macroscopic_dielectric_constant
>    df1, df2 = self.get_dielectric_function(xc=xc)
>  File "/lap/gpaw/0.8.0.8092/lib64/python2.4/site-packages/gpaw/response/df.py", line 134, in get_dielectric_function
>    dm_wGG = self.get_dielectric_matrix(xc=xc)
>  File "/lap/gpaw/0.8.0.8092/lib64/python2.4/site-packages/gpaw/response/df.py", line 47, in get_dielectric_matrix
>    self.initialize()
>  File "/lap/gpaw/0.8.0.8092/lib64/python2.4/site-packages/gpaw/response/chi.py", line 119, in initialize
>    self.parallel_init()
>  File "/lap/gpaw/0.8.0.8092/lib64/python2.4/site-packages/gpaw/response/chi.py", line 447, in parallel_init
>    assert self.Nw % (size / self.kcomm.size) == 0
> 
> 
> When kcommsize is above number of cores the calculation runs but now it is parallel over the kpoint, and I hit the memory limit. 
> 
> My response function object looks like;
> 
> df = DF(calc='out.gpw', q=q, w=w, eta=0.0001, 
>        hilbert_trans=False, txt='df_1.out',
>        ecut=150, optical_limit=True, kcommsize=1)
> 
> What am I doing wrong? Please, any help is very much appreciated. 
> 
> Cheers,
> Anders
> 
> _______________________________________________
> gpaw-users mailing list
> gpaw-users at listserv.fysik.dtu.dk
> https://listserv.fysik.dtu.dk/mailman/listinfo/gpaw-users