I have been working with an anti-ferromagnetic material Cobalt Oxide. And in the image given below the blue spheres are Co ions. The blue spheres form a tetrahedron shape.
And I've assigned the spin configuration as per this image I've taken from an online thesis.
So according to the image, the 3 Co atoms in a plane will be assigned on spin(say up) and the remaining one Co atom is assigned a down spin. I have given the code below (input file):
&CONTROL
calculation = "scf"
prefix = "CoO"
outdir = "./outdir"
pseudo_dir = "."
tprnfor = .true.
tstress = .true.
verbosity = "low"
/
&SYSTEM
ibrav = 0
A = 4.59861
nat = 8
ntyp = 3
ecutwfc = 60
ecutrho = 445
nspin = 2
starting_magnetization(1)= 1
starting_magnetization(2)= -1
occupations = "smearing"
smearing = "mv"
degauss = 0.005d0
/
&electrons
conv_thr = 1d-8
mixing_beta = 0.7d0
/
CELL_PARAMETERS {alat}
1.000000000000000 0.000000000000000 0.000000000000000
0.000000000000000 1.000000000000000 0.000000000000000
0.000000000000000 0.000000000000000 1.000000000000000
ATOMIC_SPECIES
Co 58.93300 Co.pbe-spn-kjpaw_psl.0.3.1.UPF
Co1 58.93300 Co.pbe-spn-kjpaw_psl.0.3.1.UPF
O1 15.99900 O.pbe-n-kjpaw_psl.1.0.0.UPF
ATOMIC_POSITIONS {crystal}
Co 0.250000000000000 0.750000000000000 0.750000000000000
Co1 0.250000000000000 0.250000000000000 0.250000000000000
Co 0.750000000000000 0.750000000000000 0.250000000000000
Co 0.750000000000000 0.250000000000000 0.750000000000000
O1 0.500000000000000 0.500000000000000 0.500000000000000
O1 0.500000000000000 0.000000000000000 0.000000000000000
O1 0.000000000000000 0.500000000000000 0.000000000000000
O1 0.000000000000000 0.000000000000000 0.500000000000000
K_POINTS {automatic}
17 17 17 0 0 0
But the magnetization is non-zero. which is wrong.
total magnetization = 6.01 Bohr mag/cell
absolute magnetization = 10.32 Bohr mag/cell
It would be nice if someone could shed some light on this .Thanks in advance :)