FFT problems for large cell

[Alex Vozny]

Hi I am encountering a problem when trying to increase a unit cell size.
I study a CuO slab
    &CELL
      ABC 18.4979  18.4979  70.
      ALPHA_BETA_GAMMA 90.0 90.0 120.0
    &END CELL
It works fine for this geometry.

Then I want to add another slab and increase the unit cell in Z to 110 Ang
The program crashes with
 *** ERROR in fft_radix_operations (MODULE fft_tools) ***
 ********************************************************
 *** Index to radix array not found. ***
 *** Program stopped at line number 299 of MODULE fft_tools ***
(and repeats this many times).

What can I do to fix it?
I tried to run on up to 2048 cores so I don't think it is a memory issue?

Thanks.
Alex.

[Florian Schiffmann]

Hi Alex,

seems like your cell is a whopper. Anyway, I was dealing with similar cells and the problem might be that you need to add the keyword EXTENDED_FFT_LENGTH in the GLOBAL section.

Flo

[Alex Vozny]

Thanks, Flo.
Unfortunately, this doesn't help.
Any other suggestions?
Alex.

[Florian Schiffmann]

Hmm, do you mind sending me your input file so I can run a test on our computers? I ran 120A cells before and it worked fine, so it would be good to have a 1 to 1 comparison. If you don't want to post it here, my e-mail can be found on http://www.nanosim.mat.ethz.ch/people/postdocs/florschi.

Flo

[hut...@pci.uzh.ch]

Hi

are you using FFTW? Only this library allows for those very
large FFTs.

regards

Juerg

--------------------------------------------------------------
Juerg Hutter Phone : ++41 44 635 4491
Physical Chemistry Institute FAX : ++41 44 635 6838
University of Zurich E-mail: hut...@pci.uzh.ch
Winterthurerstrasse 190
CH-8057 Zurich, Switzerland
---------------------------------------------------------------

-----cp...@googlegroups.com wrote: -----
To: cp...@googlegroups.com
From: Florian Schiffmann
Sent by: cp...@googlegroups.com
Date: 08/17/2013 11:12AM
Subject: [CP2K:4562] Re: FFT problems for large cell

--
You received this message because you are subscribed to the Google Groups "cp2k" group.
To unsubscribe from this group and stop receiving emails from it, send an email to cp2k+uns...@googlegroups.com.
To post to this group, send email to cp...@googlegroups.com.
Visit this group at http://groups.google.com/group/cp2k.
For more options, visit https://groups.google.com/groups/opt_out.

[Alex Vozny]

Thanks, Juerg.
I am using FFTSG. Will try to install FFTW3.