[Wien] ghost bands

[Dr. B.R.Sahu]

Dear W2k users

        I have a supercell(of one K + Ti) self consistent calculation with
distance of Ti from first K, d(K-Ti)=8.01 au.  In this run, I had set
d(K-Ti)=5.0 au(no core charge leakage) to begin with (ie RMT=2.5 each)  
and the calculation converged without any ghost bands(u-dot smaller than
u).I get the expected values.

I wanted to increase the RMT of K and Ti to 4.0 a.u each so that they
almost touch each other ie d(TM-A1)=8.0 au. I started the calculation all
over from scratch. This time the calculation is faster than the previous
run(due to small number of plane waves in the interstitials) but I get the
QTL-B value very large ie

QTL-B VALUE .EQ.   32.30382   !!!!!!

I understand that such a large value for QTL-B is indeed ghost band
signature in the scf calculation.

The parameters used for both runs are SAME:

RMTKMAX= 8.0

number of k-points in IBZ = 120( a dense mesh is not needed for such a
large cell but I believe it is not one of the reason for appearance of
ghost band).

unit cell size = about 20 au.

RMT(TM)=2.5 and RMT(A1)=2.5 in the first case(NO GHOST BANDS).

RMT(TM)=4.0 and RMT(A1)=4.0 in the second case(GHOST BANDS).

Is RMTKMAX=8.0 is large enough to cause ghost bands?

Here is the case.in1 file:

_______________________________________________________________________________
WFFIL        (WFPRI, SUPWF)
  8.00       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   -2.29      0.010 CONT 1
 0    0.30      0.000 CONT 1
 1   -1.07      0.010 CONT 1
 1    0.30      0.000 CONT 1
  0.30    4  0      (GLOBAL E-PARAMETER WITH n OTHER CHOICES, global 
APW/LAPW)
 0   -2.29      0.010 CONT 1
 0    0.30      0.000 CONT 1
 1   -1.07      0.010 CONT 1
 1    0.30      0.000 CONT 1
  0.30    4  0      (GLOBAL E-PARAMETER WITH n OTHER CHOICES, global 
APW/LAPW)
 0   -2.29      0.010 CONT 1
 0    0.30      0.000 CONT 1
 1   -1.07      0.010 CONT 1
 1    0.30      0.000 CONT 1
  0.30    4  0      (GLOBAL E-PARAMETER WITH n OTHER CHOICES, global 
APW/LAPW)
 0   -2.29      0.010 CONT 1
 0    0.30      0.000 CONT 1
 1   -1.07      0.010 CONT 1
 1    0.30      0.000 CONT 1
  0.30    5  0      (GLOBAL E-PARAMETER WITH n OTHER CHOICES, global 
APW/LAPW)
 0    0.30      0.000 CONT 1
 0   -4.35      0.005 STOP 1
 1   -2.58      0.010 CONT 1
 1    0.30      0.000 CONT 1
 2    0.30      0.010 CONT 1
K-VECTORS FROM UNIT:4   -9.0       2.5      emin/emax window
_______________________________________________________


where I am going wrong?pl. suggest.

best regards
sahu