WIEN2k-FAQ: FERMI 
©2001 by P. Blaha, K. Schwarz and J. Luitz 
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In some cases it may happen, that during the scf-cycle LAPW2 stops with
errors in FERMI. Possible messages are: 
'FERMI' - CANNOT FIND FERMI LEVEL 
This is due to some accidental degeneracy and in this case I recommend
to (temporarily) change the FERMI-method to GAUSS or TEMP and rerun lapw2.
A message starting with: 
'FERMI',' ELECN TO LARGE OR TO LESS ENERGIES' 
indicates that you did not find enough eigenvalues to accommodate all
valence electrons. Two possible solutions: 
- Increase Emin/Emax in case.in1 
- It is possible that some localized states could not be found (Check
if E-bottom/E-top could be found for all local orbital states in case.scf1)
and these states are therefore not calculated. Check for large charge fluctuations
in the last iterations (grep :NTO0x case.scf). Probably, the solution to
that is restarting from scratch with a smaller mixing factor in case.inm
(use e.g. 0.1 instead of 0.2). 
- Check and eventually increase NUME in $WIENROOT/SRC_LAPW1/param.inc and recompile lapw1 (make;
  make complex; cp lapw1 lapw1c ..)
Peter Blaha,