[Wien] Ghost bands error in SrTiO3 calculation at high RKmax

[Laurence Marks]

Your linearization energies look very strange. I suggest that you use
the default case.in1 and APW (is there a reason you want to use LAPW?)
For most problems that I know of -in1new is now obsolete, replaced by
-in1ef (which is done automatically with the default case.in1). Then
just increase RKMAX as appropriate, this is more important than
fiddling with the linearization energies in most cases.

N.B., what RMTs are you using, your Fermi Energy looks low to me.

On Wed, Jun 13, 2012 at 8:54 PM, Ye Zhu <ye.zhu at monash.edu> wrote:
> Hi all,
>
> I am running a calculation for SrTiO3 empty DOS using the newest version of
> WIEN2k. An error I got is
>
>            Error in LAPW2
>            'l2main' - QTL-B.GT.15., Ghostbands, check scf files
>
> which occurred during the very first round when I used RKmax = 8.  .scf2
> file shows:
>
>          QTL-B VALUE .EQ.  143.22898 in Band of energy   0.44165  ATOM=
> 1  L=  0
>           Check for ghostbands or EIGENVALUES BELOW XX messages
>           Adjust your Energy-parameters for this ATOM and L (or use -in1new
> switch), check RMTs  !!!
>
>          :WARN : QTL-B value eq. 143.23 in Band of energy   0.44165
> ATOM=    1  L=  0
>          :WARN : You should change the E-parameter for this atom and L-value
> in case.in1 (or try the -in1new switch)
>
> and I also found:                     Energy to separate low and high
> energystates: -999.00000
>
> Similar information is in .output2 :                   Energy to separate
> semicore and valence states:  -999.000000000000
>
> Why the energy to separate semicore and valence states cannot be found? I
> have tried RKmax = 6, 7, 7.5, 8.5, 9, 10, and all went through without the
> Ghostbands error. But I did see a number of warnings when RKmax > 8 :
>
> :WAR   :             1 EIGENVALUES BELOW THE ENERGY   -9.00000
> :WAR   :             1 EIGENVALUES BELOW THE ENERGY   -9.00000
> :WAR   :             1 EIGENVALUES BELOW THE ENERGY   -9.00000
>
> Is this a Emin problem? These problems at high RKmax make me worry about my
> calculation. The following is my .in1 file
>
> WFFIL  EF=.41905   (WFFIL, WFPRI, ENFIL, SUPWF)
>   8.0       10    4 (R-MT*K-MAX; MAX L IN WF, V-NMT
>  .23   6   0      global e-param with N other choices, napw
>  0    0.200     0.000 CONT 0
>  0   -2.000     0.002 CONT 0
>  1    0.240     0.000 CONT 0
>  1   -0.690     0.002 CONT 0
>  2    0.267     0.000 CONT 1
>  2    1.100     0.000 CONT 1           <<<<
>  .23   6   0      global e-param with N other choices, napw
>  0    0.155     0.000 CONT 0
>  0   -3.800     0.002 STOP 0
>  1    0.233     0.000 CONT 0
>  1   -2.000     0.002 CONT 0
>  2    0.200     0.000 CONT 1
>  2    0.800     0.000 CONT 1         <<<<<
>  .23   4   0      global e-param with N other choices, napw
>  0    0.277     0.000 CONT 0
>  0   -0.750     0.002 CONT 0
>  1    0.268     0.000 CONT 0
>  1    1.300     0.000 CONT 0        <<<<<<
> K-VECTORS FROM UNIT:4   -9.0       3.0    42   emin/emax/nband #red
>
> Most of the energies were determined using -in1new switch, and I added
> high-lying local d-orbitals for Sr (atom1) and Ti (atom2), and local
> p-orbital for O (atom3) (highlighted by arrows), hoping to improve the
> calculation for empty DOS. The energies of these high-lying orbitals were
> determined from looking at DOS plots and choosing the middle of the
> interesting energy range. I increased Emax to 3.0 Ry also for the same
> purpose. The following the the .in1 file right after -in1new for comparison:
>
> WFFIL  EF=.42815   (WFFIL, WFPRI, ENFIL, SUPWF)
>   9.00       10    4 (R-MT*K-MAX; MAX L IN WF, V-NMT
>  .22815   5   0      global e-param with N other choices, napw
>  0    0.195     0.000 CONT 0
>  0   -1.976     0.000 CONT 0
>  1    0.237     0.000 CONT 0
>  1   -0.659     0.000 CONT 0
>  2    0.267     0.000 CONT 1
>  .22815   6   0      global e-param with N other choices, napw
>  0    0.155     0.000 CONT 0
>  0   -3.689     0.001 STOP 0
>  1    0.233     0.000 CONT 0
>  1   -1.961     0.000 CONT 0
>  2    0.198     0.000 CONT 1
>  2   -0.766     0.000 CONT 1      <<<<<
>  .22815   3   0      global e-param with N other choices, napw
>  0    0.277     0.000 CONT 0
>  0   -0.781     0.000 CONT 0
>  1    0.268     0.000 CONT 0
> K-VECTORS FROM UNIT:4   -9.0       3.0    42   emin/emax/nband #red
>
> There is one local d-orbital with -0.766 Ry for Ti which I don't quite
> understand. As I care about DOS above Fermi level, I changed it to 0.8 Ry.
> The volume optimization worked fine with both .in1 files, but I am always
> worrying about my modifications. Please let me now if anyone knows what the
> problem is or needs any more information.
>
> Thank you very much,
>
> Ye



-- 
Professor Laurence Marks
Department of Materials Science and Engineering
Northwestern University
www.numis.northwestern.edu 1-847-491-3996
"Research is to see what everybody else has seen, and to think what
nobody else has thought"
Albert Szent-Gyorgi