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[uludoganmustafa@yahoo.com]

Hi
I tried to calculate the band structure of BaTiO3 using GGA-PBE exchange 
correlation formalism with OPIUM generated norm-conserving pseudopotentials. 
The behaviour of bands between M to Gamma was weird. I checked also with 
previous work done by Ph. Ghosez, X. Gonze and J. P. Michenaud, 
Ferroelectrics  Vol 220, p. 1 (1999).  My data did not seem to as smooth as 
the referenced paper in the region M-Gamma. I somehow got the feeling that 
there is a high-symmetry point between M-Gamma. Also the upper conduction 
bands acts strange which did not surprise me. I know the problem of DFT in 
band structure theory.  I followed the Tutorial example t35.in . (One step 
forward I will try it with GW.)
Am I missing something here. Here is my input file
# BaTiO3 molecule
#
# In this input file, the location of the information on this or that line
# is not important : a keyword is located by the parser, and the related
# information should follow.
# The "#" symbol indicate the beginning of a comment : the remaining
# of the line will be skipped.

#Define the different datasets
ndtset 2            

#Definition of the planewave basis set
ecut     50    
ecutsm 0.5
#Definition of the unit cell
acell   4.05202505120998654272 4.05202505120998654272 4.05202505120998654272  
Angstr   
angdeg 90 90 90

occopt   1              

ntypat 3          
znucl 56  22  8   
natom 5           
typat 1 2 3 3 3       
xred     0.0000000000000000  0.0000000000000000  0.0000000000000000    
         0.5000000000000000  0.5000000000000000  0.5000000000000000    
         0.0000000000000000  0.5000000000000000  0.5000000000000000    
         0.5000000000000000  0.0000000000000000  0.5000000000000000    
         0.5000000000000000  0.5000000000000000  0.0000000000000000    

prtvol 10

nstep 100         
ixc   11           
diemac 1.0       
                  

                 
nbdbuf 2
nband 24                

# parallelization
localrdwf 1





#Dataset 1 : usual self-consistent calculation


tolwfr1   1.0d-20
iscf1     5
getwfk1   0


kptopt1 1          # Option for the automatic generation of k points,
                   # taking into account the symmetry
nshiftk1 1
shiftk1  0.5 0.5 0.5  # These shifts will be the same for all grids
ngkpt1  20 20 20
prtden1  1         # Print the density, for use by dataset 2
prtgeo1  30
prtdos1   2

#Dataset 2 : the band structure
iscf2    -2
getden2   1
kptopt2  -5
nkpt2    62
ndivk2   10 10 14 17 10      # 10, 12 and 17 divisions of the 3 segments, 
delimited
                       # by 4 points.
kptbounds2  0.0  0.0  0.0 # Gamma point
            0.5  0.0  0.0 # X point
            0.5  0.5  0.0 # M point
            1.0  1.0  1.0 # Gamma point in another cell.
            0.5  0.5  0.5 # R
            0.5  0.5  0.0 # M point
tolwfr2  1.0d-20
enunit2  1             # Will output the eigenenergies in eV