unable to constrain moments
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unable to constrain moments
I?m trying to constrain noncollinear magnetic moments in VASP along orthogonal directions to compare the relative energetics (and dielectric functions) of various ferromagnetic configurations.
When I try to constrain all magnetic moments along a specific directions
the moments instead bleed into other directions.
I get identical results with a coupling LAMBDA = 5000 and LAMBDA = 1000000.
I?m using the default Wigner Seitz radius (RWIGS) from the POTCAR -- not sure if this is sufficient. However, I would think that the radius that VASP is integrating over to obtain the magnetization on a particular site should also be the same radius it uses to determine how much energy penalty is incurred from going ?against? the constrained magnetic moments.
How do I better constrain these moments? I've included my INCAR below and the resulting magnetization in the same format as MAGMOM.
Thanks!
========== INCAR ============
SYSTEM = LIO_H0
Startparameter for this run:
NWRITE =3
SYMPREC = 1e-6
PREC = Accurate medium, high low
ISTART = 0 job : 0-new 1-cont 2-samecut
ICHARG = 2 charge: 1-file 2-atom 10-const
EDIFF = 1E-4 stopping-criterion for ELM
EDIFFG = -5E-3
ENCUT = 400
NSW = 0 number of steps for IOM
IBRION = 1 ionic relax: 0-MD 1-quasi-New 2-CG
ISIF = 2 stress and relaxation
LORBIT = 11
ISMEAR = 0
SIGMA = 0.01
GGA = PE
NBANDS = 256
ALGO = Normal
LOPTICS = .TRUE.
CSHIFT = 0.1
NEDOS = 2000
EMIN = 0
EMAX = 15
LMAXMIX = 4
LDAU = .TRUE.
LDAUTYPE = 2
LDAUJ = 0 0 0
LDAUL = -1 -1 2
LORBMOM = .TRUE.
LPLANE = .TRUE.
NCORE = 8
LSCALU = .FALSE.
NSIM = 8
LSORBIT = .TRUE.
I_CONSTRAINED_M = 1
LAMBDA = 5000 ! or 1000000 for the second run
ISYM = 0
ENCUTGW = 150
LDAUU = 0 0 2
M_CONSTR = 120*0 0.7 0.0 0.0 0.7 0.0 0.0 0.7 0.0 0.0 0.7 0.0 0.0 0.7 0.0 0.0 0.7 0.0 0.0 0.7 0.0 0.0 0.7 0.0 0.0
MAGMOM = 120*0 0.7 0.0 0.0 0.7 0.0 0.0 0.7 0.0 0.0 0.7 0.0 0.0 0.7 0.0 0.0 0.7 0.0 0.0 0.7 0.0 0.0 0.7 0.0 0.0
========== resulting mag ============
MAGMOM = 120*0 0.222 0.36 0.0 0.222 0.36 -0.0 0.222 -0.36 -0.0 0.222 -0.36 -0.0 0.149 0.318 0.0 0.148 0.319 -0.0 0.148 -0.32 -0.0 0.148 -0.32 0.0
(identical result for LAMBDA = 1000000)
When I try to constrain all magnetic moments along a specific directions
the moments instead bleed into other directions.
I get identical results with a coupling LAMBDA = 5000 and LAMBDA = 1000000.
I?m using the default Wigner Seitz radius (RWIGS) from the POTCAR -- not sure if this is sufficient. However, I would think that the radius that VASP is integrating over to obtain the magnetization on a particular site should also be the same radius it uses to determine how much energy penalty is incurred from going ?against? the constrained magnetic moments.
How do I better constrain these moments? I've included my INCAR below and the resulting magnetization in the same format as MAGMOM.
Thanks!
========== INCAR ============
SYSTEM = LIO_H0
Startparameter for this run:
NWRITE =3
SYMPREC = 1e-6
PREC = Accurate medium, high low
ISTART = 0 job : 0-new 1-cont 2-samecut
ICHARG = 2 charge: 1-file 2-atom 10-const
EDIFF = 1E-4 stopping-criterion for ELM
EDIFFG = -5E-3
ENCUT = 400
NSW = 0 number of steps for IOM
IBRION = 1 ionic relax: 0-MD 1-quasi-New 2-CG
ISIF = 2 stress and relaxation
LORBIT = 11
ISMEAR = 0
SIGMA = 0.01
GGA = PE
NBANDS = 256
ALGO = Normal
LOPTICS = .TRUE.
CSHIFT = 0.1
NEDOS = 2000
EMIN = 0
EMAX = 15
LMAXMIX = 4
LDAU = .TRUE.
LDAUTYPE = 2
LDAUJ = 0 0 0
LDAUL = -1 -1 2
LORBMOM = .TRUE.
LPLANE = .TRUE.
NCORE = 8
LSCALU = .FALSE.
NSIM = 8
LSORBIT = .TRUE.
I_CONSTRAINED_M = 1
LAMBDA = 5000 ! or 1000000 for the second run
ISYM = 0
ENCUTGW = 150
LDAUU = 0 0 2
M_CONSTR = 120*0 0.7 0.0 0.0 0.7 0.0 0.0 0.7 0.0 0.0 0.7 0.0 0.0 0.7 0.0 0.0 0.7 0.0 0.0 0.7 0.0 0.0 0.7 0.0 0.0
MAGMOM = 120*0 0.7 0.0 0.0 0.7 0.0 0.0 0.7 0.0 0.0 0.7 0.0 0.0 0.7 0.0 0.0 0.7 0.0 0.0 0.7 0.0 0.0 0.7 0.0 0.0
========== resulting mag ============
MAGMOM = 120*0 0.222 0.36 0.0 0.222 0.36 -0.0 0.222 -0.36 -0.0 0.222 -0.36 -0.0 0.149 0.318 0.0 0.148 0.319 -0.0 0.148 -0.32 -0.0 0.148 -0.32 0.0
(identical result for LAMBDA = 1000000)
Last edited by tsmidt on Tue Jul 08, 2014 4:44 am, edited 1 time in total.
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- Global Moderator
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Re: unable to constrain moments
Hi,
We're sorry that we didn’t answer your question. This does not live up to the quality of support that we aim to provide. The team has since expanded. If we can still help with your problem, please ask again in a new post, linking to this one, and we will answer as quickly as possible.
Best wishes,
VASP