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magnetic anisotropy energy calculated seems wrong!
Date: 2016/09/17 16:51
Name: Shekoufe Khosravi   <shekoufe.khosravi@gmail.com>

Dear All

I tried to calculate the magnetic anisotropy energy of (Fe3O4)2 cluster using openmx
but terrible large values obtained for difference between energy of two direction for
magnetization (~10 eV).

90-0.o: Uele = -117.755566896922
90-30.o: Uele = -117.307718413400
90-60.o: Uele = -117.361350040335
90-90.o: Uele = -118.046402815599

# File Name
System.CurrrentDirectory ./ # default=./
System.Name so-90-0
level.of.stdout 1 # default=1 (1-3)
level.of.fileout 1 # default=1 (0-2)
DATA.PATH ../DFT_DATA13/ # default=../DFT_DATA/
#
# Definition of Atomic Species
#

Species.Number 2
<Definition.of.Atomic.Species
Fe Fe6.0S-s2p2d2f1 Fe_PBE13S
O O5.0-s2p2d1 O_PBE13
Definition.of.Atomic.Species>

#
# Atoms
#
Atoms.Number 14
Atoms.SpeciesAndCoordinates.Unit Ang # Ang|AU
<Atoms.SpeciesAndCoordinates # Unit=Ang.
1 Fe 13.774020 13.551720 14.999969 8.0 6.0 90 0 90 0 1 off
2 Fe 15.001770 15.432930 16.229309 8.0 6.0 90 0 90 0 1 off
3 Fe 12.786839 15.679709 14.999491 8.0 6.0 90 0 90 0 1 off
4 Fe 17.211449 15.680430 15.003449 8.0 6.0 90 0 90 0 1 off
5 Fe 14.997510 15.438540 13.774320 8.0 6.0 90 0 90 0 1 off
6 Fe 16.225561 13.555110 14.997240 8.0 6.0 90 0 90 0 1 off
7 O 12.144540 14.069850 14.999310 3.0 3.0 90 0 90 0 0 off
8 O 16.509480 16.323330 16.417561 3.0 3.0 90 0 90 0 0 off
9 O 13.490610 16.314510 16.422510 3.0 3.0 90 0 90 0 0 off
10 O 13.488300 16.324200 13.583099 3.0 3.0 90 0 90 0 0 off
11 O 15.000151 13.628730 13.650960 3.0 3.0 90 0 90 0 0 off
12 O 16.514669 16.314240 13.579800 3.0 3.0 90 0 90 0 0 off
13 O 15.001620 13.619100 16.342350 3.0 3.0 90 0 90 0 0 off
14 O 17.853451 14.067571 15.000690 3.0 3.0 90 0 90 0 0 off
Atoms.SpeciesAndCoordinates>
Atoms.UnitVectors.Unit Ang # Ang|AU
Atoms.SpeciesAndCoordinates>

Atoms.UnitVectors.Unit Ang # Ang|AU
<Atoms.UnitVectors # unit=Ang.
12.500 0.0000 0.0000
0.0000 10.000 0.0000
0.0000 0.0000 10.500
Atoms.UnitVectors>


#
# SCF or Electronic System
#

scf.XcType GGA-PBE # LDA|LSDA-CA|LSDA-PW|GGA-PBE
scf.Hubbard.U off # On|Off , default=off
scf.SpinPolarization NC # On|Off|NC
scf.SpinOrbit.Coupling on # On|Off, default=off
scf.ElectronicTemperature 300.0 # default=300 (K)
scf.energycutoff 200.0 # default=150 (Ry)
scf.maxIter 2000 # default=40
scf.EigenvalueSolver Cluster # Recursion|Cluster|Band
scf.Kgrid 1 1 1 # means 4x4x4
scf.Mixing.Type rmm-diis # Simple|Rmm-Diis|Gr-Pulay|Kerker|Rmm-Diisk
scf.Constraint.NC.Spin on # on|off, default=off
scf.Constraint.NC.Spin.v 1 # default=0.0(eV)
scf.Init.Mixing.Weight 0.01 # default=0.30
scf.Min.Mixing.Weight 0.001 # default=0.001
scf.Max.Mixing.Weight 0.01 # default=0.40
scf.Mixing.History 30 # default=5
scf.Mixing.StartPulay 10 # default=6
scf.criterion 1.0e-4 # default=1.0e-6 (Hartree)

Then I changed to some other test cases the last one is hcp Co crystal.
But now the MAE obtained by openmx with the following input-file, is inconsistent with reported K1 for
this crystal.

Ex - Ez= 0.004896 eV
K1= 45micro eV/atom =0.000090 eV/cell




# Co - hcp
System.CurrrentDirectory ./hcp/. # default=./
System.Name co-0
level.of.stdout 1 # default=1 (1-3)
level.of.fileout 1 # default=1 (0-2)
DATA.PATH ../DFT_DATA13/ # default=../DFT_DATA/
#
# Definition of Atomic Species
#

Species.Number 1
<Definition.of.Atomic.Species
Co Co6.0S-s3p2d1 Co_PBE13S
Definition.of.Atomic.Species>

#
# Atoms
#
Atoms.Number 2
Atoms.SpeciesAndCoordinates.Unit FRAC # Ang|AU
<Atoms.SpeciesAndCoordinates # Unit=Ang.
1 Co 0.0000 0.0000 0.00 9 6 0 0 0 0 1 off
2 Co 0.6667 0.3334 0.50 9 6 0 0 0 0 1 off
Atoms.SpeciesAndCoordinates>
Atoms.UnitVectors.Unit Ang # Ang|AU
<Atoms.UnitVectors # unit=Ang.
2.507 0.0000 0.0000
1.2535 3.4246 0.0000
0.0000 0.0000 4.0695
Atoms.UnitVectors>

#
# SCF or Electronic System
#

scf.XcType GGA-PBE # LDA|LSDA-CA|LSDA-PW|GGA-PBE
scf.Hubbard.U off # On|Off , default=off
scf.SpinPolarization NC # On|Off|NC
scf.SpinOrbit.Coupling on # On|Off, default=off
scf.ElectronicTemperature 450.0 # default=300 (K)
scf.energycutoff 200.0 # default=150 (Ry)
scf.maxIter 2000 # default=40
scf.EigenvalueSolver Band # Recursion|Cluster|Band
scf.Kgrid 10 10 6 # means 4x4x4
scf.Mixing.Type rmm-diis # Simple|Rmm-Diis|Gr-Pulay|Kerker|Rmm-Diisk
scf.Constraint.NC.Spin on # on|off, default=off
scf.Constraint.NC.Spin.v 1 # default=0.0(eV)
scf.Init.Mixing.Weight 0.014 # default=0.30
scf.Min.Mixing.Weight 0.0014 # default=0.001
scf.Max.Mixing.Weight 0.014 # default=0.40
scf.Mixing.History 30 # default=5
scf.Mixing.History 7 # default=5
scf.Mixing.StartPulay 15
scf.Mixing.EveryPulay 8
scf.Kerker.factor 6.0
scf.criterion 1.0e-6 # default=1.0e-6 (Hartree)
restart.scf off


would you please mention me any mistake in my work?

Thanks in Advance.
Shekoufe Khosravi
メンテ
Page: [1]

Re: magnetic anisotropy energy calculated seems wrong! ( No.1 )
Date: 2016/09/21 18:53
Name: Artem Pulkin

Well, when I was doing similar stuff I had to switch to LDA+U. Otherwise DFT fails.
メンテ
Re: magnetic anisotropy energy calculated seems wrong! ( No.2 )
Date: 2016/10/16 19:01
Name: T. Ozaki

Hi,

> 90-0.o: Uele = -117.755566896922
> 90-30.o: Uele = -117.307718413400
> 90-60.o: Uele = -117.361350040335
> 90-90.o: Uele = -118.046402815599

Why did you use Uele instead of Utot?
The analysis should be done using Utot.
Also, I wonder that you got enough SCF convergence and trace
the energy surface smoothly without having an erratic jump.

Regards,

TO
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Page: [1]

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