[Wien] could not understand how to apply scissors operator even after going through UG and mailing list

[Dr. K. C. Bhamu]

Dear Experts

I tried to get band structure of wide band gap semiconductor. When I
preformed usual DFT of DFT+U, I see my Ef is at VBM. But when I calculated
PBE+mBJ+U, my VBM shifted down (if some one want to see, I will email it as
it is not possible to attach here) by a value of -1.24689eV at M point,
-1.24913eV at H point.

So, by going through literature and from mailing list, I came to know that
I have to apply scissors operator.
I went through the following important links

http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg11416.html
http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg02523.html
http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg14559.html
http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg13025.html

to see how I can apply this operation.
I could not get perfectly and puzzling, how to apply scissors operator.

If I understood well then I should convert above mentioned energy into Ry
and put into the following case files:

1) *case.int <http://case.int> for DOSS, **but where?*
pbe             #Title
 -1.50   0.002   3.500  0.003   #Emin, DE, Emax, Gauss-Broad
  11   N   0.000                 #Number of DOS-cases,G/L/B broadening (Ry)

2) *in case.insp for band *
### Data configuration
-21.0  12.0  2                      # energy range, energy switch (1:Ry,
2:eV)
1      0.5362044322                      # Fermi switch,  Fermi-level (in
Ry units)    * >> If i am not wrong, I should add the rubbish energy into
this Ef*
1   999                            # number of bands for heavier plotting
1,1
0      1    0.2                    # jatom, jtype, size  of heavier plotting

 and

3) *in case.inkram*

  0.1    Gamma: broadening of interband spectrum
  0.0    energy shift (scissors operator)                         >>>>>
     *here?? *
  0      add intraband contributions? yes/no: 1/0
 12.60   plasma frequencies  (from joint, opt 6)
  0.20   Gammas for Drude terms


*Now another query is:*
Form the below dispersion curve, I am getting VBM at H but there is a small
bump (peak) between K and G point which is 0.14eV towards the Ef.
Can ignore this value? or I should apply this value (-1.1898eV or
-0.0874486553Ryd) for scissors operator?




Sincerely
Bhamu
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