[Pw_forum] segmentation faults in pwcond.x

Alexander Smogunov smogunov at sissa.it
Thu Feb 26 08:56:29 CET 2009


Dear Derek
Try to use 8 or 16 CPUs, unfortunately the pwcond is supposed to run
with 2^n (n integer) CPUs, we should put the check of that ...
Regards, Alexander
  
On Wednesday 25 February 2009 20:14, Derek Stewart wrote:
> Hi everyone,
>
> I am trying to do some calculations with pwcond to determine the complex
> band structure for a fairly large unit cell structure (22 atoms).  I am
> using QE version 4.0.4 compiled with the intel compilers (ifort & icc
> v10.1, mkl 10.0.4) in parallel with lam-mpi 7.1.4.  I have no problem
> running the scf calculation.
>
> However, my pwcond calculation crashes after printing out the atomic
> positions and the following lines:
>
>         k(    1) = (   0.0000000   0.0000000), wk =   1.0000000
>
>  ngper, shell number =          951         256
>  ngper, n2d =          951         212
> forrtl: severe (174): SIGSEGV, segmentation fault occurred
> Image              PC        Routine            Line        Source
> Stack trace terminated abnormally.
> forrtl: severe (174): SIGSEGV, segmentation fault occurred
> Image              PC        Routine            Line        Source
>
> The run was done in parallel over 10 processors.  I have set the stack as
> unlimited.
>
> Looking back through the pwscf archive, it appears that other people have
> run into segmenation faults at a similar point in their calculation.  It
> was mentioned that pwcond performs a diagonilization over a non-symmetric
> matrix that occasionally crashes.  Has this issue been resolved?  Also, are
> there problems with larger systems for pwcond and total RAM required?
>
> All my parameters for the pwcond input file are similar to those used in
> example12.
>
> Any suggestions would be greatly appreciated!
>
> Thanks,
>
> Derek
>
>
> ################################
> Derek Stewart, Ph. D.
> Scientific Computation Associate
> http://www.people.cornell.edu/pages/das248/
> 250 Duffield Hall
> Cornell Nanoscale Facility (CNF)
> Ithaca, NY 14853
> stewart (at) cnf.cornell.edu
> (607) 255-2856
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