[Wien] General question about ghost bands

[jadhikari@clarku.edu]

Dear WIEN2k users,

I fix the ghost band problem on one of the atoms (QTL-B values vanishes)
and it switches to other atom. And when the ghost band on the second atom
is gone, it starts on another atom. This continues for many atoms and
sometimes repeating on the already solved atoms. I have been removing
ghost bands by changing energy as suggested by scf2 or scf1 or output
files and also by varying RMT and RKmax and using different k-points in
IBZ. Few of the times I changed Gmax and XC-potential and the Emax-Emin
values. The smearing method is TEMP with 0.002 (after trying other
options)and mixing of 0.10 or 0.05.

My general question is-

" Is it a usual and common outcome to get GHOST BANDS on atoms from one to
another repeatedly and even on the ones already solved?"

The case is with the acidic form of Potassium Calcium Niobate, where I get
the ghost band for Hydrogen atom with QTL-B of 6.2 (the minimum that could
be obtained till today). After altering the energy level and changing RMT
it is gone but there starts a ghost band on Calcium atom. It dissappears
for a while and starts on Oxygen atom. Eventually it keeps rotating on
different atoms. This is with 3 k-points in IBZ as the calculation with 1
k-point in IBZ converged without any ghost band. 6 k-points in IBZ did not
move forward from lapw2 step as the previous calculation had a small QTL-B
value.

Any suggestions would be gratefully appreciated.
Thanking you.

Sincerely,

Subin Adhikari
Clark University