[Pw_forum] Segmentation fault in bands.x

Paolo Giannozzi paolo.giannozzi at uniud.it
Tue Feb 25 20:56:47 CET 2014

On Tue, 2014-02-25 at 12:29 -0500, Keivan Esfarjani wrote:

> about a week ago I sent this message about getting segmentation fault error when running bands.x on the QE examples, and got no answer.
> I could not find anything related to this in the previous discussions in the forum.

but you could have found this in the FAQ:

> In another similar run for SiC, [...]
>      Error in routine punch_band_2d (1):
>      Problems with k points
> In this case, the message says problems with kpoints,
> but pw.x ran the previous band structure calculation job with success.

$ grep 'Problems with k points' PP/src/*f90
PP/src/bands.f90:                                    'Problems with k

The error is in PP/src/bands.f90, subroutine punch_band_2d. Its header
!  This routine opens a file for each band and writes on output
!  kx, ky, energy,
!  kx, ky, energy
!  .., .., ..
!  where kx and ky are proportional to the length
!  of the vectors k_1 and k_2 specified in the input of the 2d plot.
!  The k points are supposed to be in the form
!  xk(i,j) = xk_0 + dkx *(i-1) + dky * (j-1)      1<i<n1, 1<j<n2
!  kx(i,j) = (i-1) |dkx|
!  ky(i,j) = (j-1) |dky|

are those conditions verified?

Paolo Giannozzi, Dept. Chemistry&Physics&Environment, 
Univ. Udine, via delle Scienze 208, 33100 Udine, Italy
Phone +39-0432-558216, fax +39-0432-558222 

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