[Wien] SECLR4 error in large supercells / high number of k points

[Kurt Lejaeghere]

Dear WIEN mailing list members

while using WIEN2k version 9.2 for a system containing Fe and Mo I  
obtained the following notification in *lapw1*.error:

  Cholesky INFO =         3166
  'SECLR4' - POTRF (Scalapack/LAPACK) failed.

The studied case is a 64-atom supercell of Fe/Mo containing Mo/Fe  
impurities. This error occurs as soon as the size of the supercell or  
the number of k-points becomes too large. After browsing through the  
mailing list, I found this error can occur in a number of cases, with  
a variety of possible causes. The solution is not as easy as two  
overlapping atoms. The problem resembles

http://zeus.theochem.tuwien.ac.at/pipermail/wien/2006-October/007971.html


but the solution proposed in

http://zeus.theochem.tuwien.ac.at/pipermail/wien/2007-September/009724.html

does not work in my case, since the problem does not occur at the LO  
coefficients, but further. For example in case.output1dn_10 (where the  
error occurs at the very end) I obtain:

      K=   0.89474   0.47368  -0.15789          208
       MATRIX SIZE 3705  WEIGHT=48.00  PGR:
      EIGENVALUES ARE:
      -5.2553427   -3.4536147   -3.4519203   -3.4508302   -3.4491568
      -3.4455076   -3.4450189   -3.4434554   -3.4433002   -3.4430847
      -3.4423217   -3.4406247   -3.4399921   -3.4393338   -3.4392715
      -3.4385077   -3.4381873   -3.4380193   -3.4378560   -3.4375117
      -3.4360709   -3.4359494   -3.4358333   -3.4354174   -3.4350120
      -3.4343914   -3.4328851   -3.4325970   -3.4307198   -3.4294717
      -3.4278116   -3.4276248   -2.7639594   -2.7639589   -2.7639584
(...)
       1.7762388    1.8232372    1.8316494    1.8410636    1.8474444
       1.8539221    1.8655600    1.8731463    1.8814693    1.8866394
       1.8955957    1.9015362    1.9056197    1.9286860    1.9344532
       1.9411832    1.9447140    1.9454413    1.9509334    1.9535638
       1.9605156    1.9634609    1.9652118    1.9798407    1.9821146
       1.9896013    1.9966855
             0 EIGENVALUES BELOW THE ENERGY  -10.00000
        ********************************************************

  Matrix size         3697
          allocate HS       104.3 MB
          allocate Z         52.1 MB
      allocate spanel         3.6 MB          dimensions  3697   128
      allocate hpanel         3.6 MB          dimensions  3697   128
    allocate spanelus         3.6 MB          dimensions  3697   128
        allocate slen         3.6 MB          dimensions  3697   128
          allocate x2         3.6 MB          dimensions  3697   128
    allocate legendre        46.9 MB          dimensions  3697    13   128
allocate al,bl (row)         1.2 MB          dimensions  3697    11
allocate al,bl (col)         0.0 MB          dimensions   128    11
          allocate YL         7.2 MB          dimensions    15  3697     8
Time for al,bl    (hamilt) :          0.3
Time for legendre (hamilt) :          0.4
Time for phase    (hamilt) :          3.7
Time for us       (hamilt) :          1.2
Time for overlaps (hamilt) :          1.8
Time for distrib  (hamilt) :          0.1
Time for iouter   (hamilt) :          7.6
  number of local orbitals, nlo (hamilt)      416
        allocate YL           7.2 MB          dimensions    15  3697     8
        allocate phsc         0.1 MB          dimensions  3697
Time for los      (hamilt) :          1.7
Time for alm         (hns) :          0.1
Time for vector      (hns) :          0.7
Time for vector2     (hns) :          0.6
Time for VxV         (hns) :          7.5
Wall Time for VxV    (hns) :          0.2
  Cholesky INFO =         3166

For case.in1 I used the following linearization energies (-in1ef used):

  .84535   5  0      (GLOBAL E-PARAMETER WITH n OTHER CHOICES, global APW/LAPW)
  0   .84535     0.000 CONT 1
  0   -6.50      0.001 STOP 1
  1   .84535     0.000 CONT 1
  1   -3.97      0.001 STOP 1
  2   .84535     0.005 CONT 1
  .84535   5  0      (GLOBAL E-PARAMETER WITH n OTHER CHOICES, global APW/LAPW)
  0   .84535     0.000 CONT 1
  0   -4.62      0.001 STOP 1
  1   -2.65      0.002 CONT 1
  1   .84535     0.000 CONT 1
  2   .84535     0.005 CONT 1

Thank you

With kind regards

Kurt Lejaeghere
Ghent University