ABINIT Discussion Forums

Hello,
i am calculating band gap of BiFeo3 with LDA.i could run my job but i have unphysical results means i don't have any band gap for BiFeo3.
could you please read my input file and tell me what i can't get any band gap?
input file:
ndtset 2
kptopt1 1
nshiftk1 1
shiftk1 0.5 0.5 0.5
ngkpt1 10 10 10
prtden1 1
toldfe1 1.0d-6
iscf2 -2
getden2 -1
kptopt2 -5
nband2 40
ndivk2 40 40 60 80 80
kptbounds2 0.5 0.0 -0.5
0.0 0.0 0.0
0.5 0.5 0.5
1.0 0.5 0.0
1.0 0.0 0.0
1.0 0.5 0.5
tolwfr2 1.0d-6
enunit2 1
acell 3*5.6364 angstrom
angdeg 60 60 60
ntypat 3
znucl 83 26 8
natom 10
typat 1 1 2 2 3 3 3 3 3 3
xred 0.000000000 0.000000000 0.000000000
0.500000000 0.500000000 0.500000000
0.220770001 0.220770001 0.220770001
0.720770001 0.720770001 0.720770001
0.527899981 0.933300018 0.394800007
0.394800007 0.527899981 0.933300018
0.933300018 0.394800007 0.527899981
0.894800007 0.433299989 0.027899999
0.433299989 0.027899999 0.894800007
0.027899999 0.894800007 0.433299989
ecut 20
nstep 100
diemac 2.5
Best regards.

This is too vague (read the nettiquette!)

you need to make sure your calculation is converged, and that the LDA is not just underestimating the gap (to 0 or even negative). Check the literature to see if other calculations give a gap.

M.