ABINIT Discussion Forums

My crystal complex has totally 144 valence electrons and 72 band in fhi pseudopotential.
But after optimization and energy calculations, bands are found 78 and valence electrons are 156 electrons.

Why?

the system is relaxed and i uses optcell = 1, 3, 7 and other pseudopotentials. But, it didn't change. Help pls.

You should post your input file and link the pseudo you used. You should recover the correct number of electrons/bands.
You may have missed something.

My imput file:

#-----------------------------------------------------------

#optcell

optcell 1
ionmov 3
ntime 150
dilatmx 1.04
ecutsm 0.5
toldfe 1.0d-6
iscf 7
nband 138
#-----------------------------------------------------------


# Data common to the three different datasets

# Definition of the unit cell:
acell 5.39840 8.30183 4.46013 Angstrom
angdeg 90 90 90
nstep 100
prtcif 1
ecut 74
npulayit 16
nline 12
optforces 1
prtden 1

# Definition of the atoms
znucl 28 8 5
ntypat 3
natom 22
typat 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 2 2 3 3 3 3
xred
0.000000 0.000000 0.000000
0.500000 0.500000 0.500000
0.000000 0.316280 0.500000
0.000000 0.683720 0.500000
0.500000 0.183720 0.000000
0.500000 0.816280 0.000000
0.676100 0.000000 0.247600
0.323900 0.000000 0.752400
0.176100 0.500000 0.252400
0.823900 0.500000 0.747600
0.796900 0.139600 0.698100
0.203100 0.860400 0.301900
0.203100 0.139600 0.301900
0.796900 0.860400 0.698100
0.296900 0.360400 0.801900
0.703100 0.639600 0.198100
0.703100 0.360400 0.198100
0.296900 0.639600 0.801900
0.747500 0.000000 0.541000
0.252500 0.000000 0.459000
0.247500 0.500000 0.959000
0.752500 0.500000 0.041000


# Definition of the k-point grid
kptopt 1
ngkpt 4 4 4
nshiftk 1
shiftk 0.0 0.0 0.0

#-----------------------------------------------------------

Pseudopotential is in the link:http://www.abinit.org/downloads/psp-links/lda_fhi (6Ni, 4B, 12O)

Help pls...

In the input file you posted, you impose nband = 138 which is of course not enough.
If I remove this input parameter and let abinit decide, I have 75 bands which is 3 bands more than what is needed.
By default, abinit tries to give a semiconductor so it requires to have some additional bands to calculate the fundamental band gap, optical band gap and so on.
If you check the occ variable at the beginning of the calculation you will notice than only 72 bands are filled with 2 electrons and 3 are empty so the number of electrons is the same as in the pseudo.

Thanks...

But i have used also 500 bands. occopt 7, occopt 3, again default settings(75 bands). But it didnt change. Everytime band gap is between 78 and 79. But it must be between 72 and 73. Help pls?