Constraining the value of the magnetic moment

[ritam_chakraborty]

Dear VASP users,

I am trying to perform a constrained magnetization calculation of an organic molecule which has two Fe atoms in the DFT+U framework. I am being unable to converge the system to S = 2 state (high spin). It is always going to S = 1 state, even using constrained magnetization calculation. I just want to constrain the magnetization on Fe. My input file is as follows:

ISTART = 0; ICHARG = 2

SYSTEM = gas-phase-molecule
NCORE = 8
ENCUT = 600
EDIFF = 1e-6
EDIFFG = -0.05
ISIF = 2
IBRION = 1
POTIM = 0.5
NSW = 500
NELM = 600
LREAL = False
ALGO = Fast

ISMEAR = 2
SIGMA = 0.2
LORBIT = 11

ISPIN = 2
MAGMOM = 2*3.3 64*0.0 20*0.0 8*0.0 4*0.0
I_CONSTRAINED_M = 2
M_CONSTR = 0.0 0.0 3.3 0.0 0.0 3.3 64*0.0 64*0.0 64*0.0 20*0.0 20*0.0 20*0.0 8*0.0 8*0.0 8*0.0 4*0.0 4*0.0 4*0.0
RWIGS = 1.32 0.76 0.31 0.71 0.66 ## Covalent radius of the atoms taken from web
LAMBDA = 10

GGA = MK
PARAM1 = 0.1234
PARAM2 = 0.711357
AGGAC = 0.0
LUSE_VDW = .TRUE.
ZAB_VDW = -1.8867
LASPH = .TRUE.


LDAU = .TRUE.
LDAUTYPE = 2
LDAUL = 2 -1 -1 -1 -1 -1
LDAUU = 5.00 0.00 0.00 0.00 0.00 0.00
LDAUJ = 1.00 0.00 0.00 0.00 0.00 0.00
LDAUPRINT = 2
LMAXMIX = 4


Can you tell me where I am going wrong? Or do I need to add something else? Any suggestion in this regard will be of much help.

Thanks, and best regards,
Ritam

[henrique_miranda]

Could you share your POSCAR, KPOINTS and OUTCAR file?

[ritam_chakraborty]

Dear Henrique,

Sorry for the late reply. Since I had deleted the files I had to re-run. Please find the attached zip file containing the INCAR, POSCAR, OUTCAR and KPOINTS file. I need to achieve high-spin (S = 2) state.

Thanks, and best regards,
Ritam