[Wien] about famous QTL-B and ghostband problem

[Peter Blaha]

Your scf results are ok, because all occupied states are ok.
For the DOS, however, also unoccupied states are calculated and it was 
found that at high energy (2.3 Ry) some ghostbands appear.

You can ignore it if not interested in high DOS or:
2 ways of fixing: either reduce the EMAX in case.in1, so that these high 
eigenvalues are not written, or, better, adjust (increase) the E-parameter 
for atom=2 l=1 to a larger value (maybe 1.5 Ry as first guess)

>    I am using spin orbit and LDA+U to calculate a system with Na+ ions.
> The scf finished normally without any such message like
> "Check for ghostbands or EIGENVALUES BELOW XX messages" in 
> case.output2up/dn file.
> However, when I calculate the DOS using:
> x lapw2 -qtl -up -so
> x lapw2 -qtl -dn -so
> 
> I found in case.output2up file: 
>   QTL-B VALUE .EQ.   34.42258   in Band of energy    2.31653   ATOM=    
> 2   L=  1
>     Check for ghostbands or EIGENVALUES BELOW XX messages
>     Adjust your Energy-parameters or use -in1new switch, check RMTs  !!!
> 
> My .in1 file for Na looks like:
> WFFIL        (WFPRI, SUPWF)
>   7.00       10    4 (R-MT*K-MAX; MAX L IN WF, V-NMT
>   ...
>  0.30    4  0      (GLOBAL E-PARAMETER WITH n OTHER CHOICES, global 
> APW/LAPW)
>  0    0.30      0.000 CONT 1
>  0   -3.86      0.005 STOP 1
>  1   -1.80      0.010 CONT 1
>  1    0.30      0.000 CONT 1
>   ...
> K-VECTORS FROM UNIT:4   -7.8       2.5      emin/emax window
> 
> The fermi energy is  0.56930 Ry.
> Apparently, the ghostband (if it is) is located in very high energy and is
> related to the LO orbital for Na p orbital  with energy parameter  0.30.
> My questions are:
> Is my scf result correct?
> Should I  change 0.30 to some other high value (such as 1.3 Ry) and 
> restart scf?
> Is this unoccupied LO for Na p orbital necessary?
> Or can I ignore this since I am not interested in the DOS with energy 
> higher than 2 Ry?
> 
> Thank you very much.
> 
> Best regards,
> Hongjun Xiang
> 
> =============================================================
>  H. J. Xiang
>  Postdoctoral Research Assistant
>  Department of Chemistry
>  North Carolina State University
>  Raleigh, NC 27695-8204
>  Tel: 001-919-515-8919 
>  http://www4.ncsu.edu/~hxiang/
> =============================================================
> 
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> 


                                      P.Blaha
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Peter BLAHA, Inst.f. Materials Chemistry, TU Vienna, A-1060 Vienna
Phone: +43-1-58801-15671             FAX: +43-1-58801-15698
Email: blaha at theochem.tuwien.ac.at    WWW: http://info.tuwien.ac.at/theochem/
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