spin polarized calculation

[jelenajelic]

I have problems with calculation of L12 Fe3Pt bulk structure. Here is my INCAR file
ENCUT = 500.000
PREC = NORMAL
ISPIN = 2 spin polarized calculation
NELM = 400; NELMDL= 0 # of ELM steps
EDIFF = 0.1E-03 stopping-criterion for ELM

Ionic Relaxation
EDIFFG = 0.1E-02 stopping-criterion for IOM
NSW = 200 number of steps for IOM
IBRION = 2 ionic relax: 0-MD 1-quasi-New 2-CG
POTIM = 0.5 time-step for ion-motion
ISIF = 7
GGA = 91
VOSKOWN = 1
ISYM = 0
ISMEAR = 1
SIGMA= 0.2

Electronic Relaxation 2
IALGO = 48 algorithm
LWAVE = F
LCHARG = F
LREAL = F real-space projection

NSIM = 4
NPAR = 4
LPLANE = T
LSCALU = F
As a result I got mag= -0.0103, which is wrong for Fe alloy.
Thank's for any advice

[forsdan]

It's possible that you have reached a local minima corresponding to a nonmagnetic solution. If you known the magnetic structure from experiments or earlier calculations you should specify the MAGMOM (containing the initial guess for each atom) as the experimental value times a constant like 1.2 or 1.5. That should help you reach the global minimum, since the starting guess is closer to the real solution. If you don't specify MAGMOM it will automatically set all values to 1.

NOTE: I have assumed that you have doublechecked your geometry and entered it in correct units. Otherwise if you have gotten the geometry wrong the magnetic solution could of course be different.

SIDE NOTE: Why do you set NELMDL = 0? I would at least keep the default setting.

Best regards,
/Dan Fors

<span class='smallblacktext'>[ Edited Wed Jul 30 2008, 12:21PM ]</span>

[jelenajelic]

Thank you very much for your help! It worked well with MAGMOM included.
Best regards,
Jelena