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Hi,
Please i need comment on my input file and the attached band structure plot.
############################################################
# GS + Band Structure + Fermi Surface calculation for MgB2
############################################################

ndtset 3

#Dataset 1 : GS calculation
kptopt1 1 # Use symmetry and treat only inequivalent points
ngkpt1 6 6 6
nshiftk1 1
shiftk1 0.0 0.0 0.5 # This choice preserves the hexagonal symmetry of the grid,
occopt1 1
nband1 26
prtden1 1
tolvrs1 1.0d-18

#Dataset 2 : Band structure calculation
iscf2 -2
getden2 -1
kptopt2 -5
tolwfr2 1.0d-12
nband2 40
ndivk2 60 60 60 60 60 60 #
kptbounds2 0.0 0.0 0.0 #Gamma
0.0 0.0 0.5 #A
0.3 0.3 0.5 #H
0.3 0.3 0.0 #K
0.0 0.0 0.0 #Gamma
0.5 0.0 0.0 #M
0.3 0.3 0.0 #K

enunit2 1

#Dataset 3 : Output of the Fermi surface
prtfsurf3 1 # To output the FS
getwfk3 -1
iscf3 -3 # NSCF calculation, occupancies and Fermi level are calculated once convergence is achieved.
# It should give the same FS as a GS calculation provided that the two
# k-meshes are sufficiently dense.
getden3 1
occopt3 1
nband3 40
kptopt3 1
ngkpt3 8 8 8 # too coarse. 24 24 24 for a reasonable FS
shiftk3 0.0 0.0 0.0 # Shifted grids are not supported by Xcrysden.
tolwfr3 1.0d-12

#COMMON INPUT DATA###########################################################
#
ecut 60
ecutsm 0.5
nstep 100

# MgB2 lattice structure
ntypat 2
znucl 12 5
natom 3
typat 1 2 2

#Definition of the unit cell
acell 2*5.8421069568E+00 6.5137931664E+00

#rprim 1.0000000000E+00 0.0000000000E+00 0.0000000000E+00
# -5.0000000000E-01 8.6602540378E-01 0.0000000000E+00
# 0.0000000000E+00 0.0000000000E+00 1.0000000000E+00
angdeg 90 90 120
spgroup 191
brvltt -1
# Atomic positions
xred 0.00 0.00 0.00 #Mg1
1/3 2/3 1/2 #B2
2/3 1/3 1/2 #B2


ixc 11
timopt 2

Thanks for your usuall assistance