Check symmetry breaking under influence of SOI and/or electric charge

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Check symmetry breaking under influence of SOI and/or electric charge

Date: 2022/03/26 13:09
Name: Bagus <bagusnuryasin_3225160838@mhs.unj.ac.id>: Dear OpenMX users,

I would like to examine symmetry breaking under the influence of SOC and/or electric field to confirm band splitting and/or band structure shifting. However, after doing the calculations, there is no change in atomic distance Ni-Br or atomic angle Ni-Br-Ni when I visualize the .xyz and .bulk.xyz output files on VESTA.

how to check that symmetry break? any input errors in the .dat file? any recommendations to confirm band splitting and/or band structure shifting?

here's my .dat file

### (base) non-collinear NiBr2 monolayer without SOC and electric field
#
# Definition of Atomic Species
#
Species.Number 2
<Definition.of.Atomic.Species
Br Br7.0-s3p3d2 Br_PBE19
Ni Ni6.0S-s3p3d2f1 Ni_PBE19S
Definition.of.Atomic.Species>

#
# Atoms
#
Atoms.Number 3
Atoms.SpeciesAndCoordinates.Unit FRAC # Ang|AU
<Atoms.SpeciesAndCoordinates
1 Ni 0.00000000000000 0.00000000000000 0.00000000000000 10.0 6.0 0.0 0.0 0.0 0.0 0 off
2 Br 0.33364644113299 0.66610406570644 0.08017052963226 3.5 3.5 0.0 0.0 0.0 0.0 0 off
3 Br 0.66635356275338 0.33389594190917 0.91982946734286 3.5 3.5 0.0 0.0 0.0 0.0 0 off
Atoms.SpeciesAndCoordinates>

Atoms.UnitVectors.Unit Ang
<Atoms.UnitVectors
3.700000000000000 0.000000000000000 0.000000000000000
-1.850000000000000 3.204294000000000 0.000000000000000
0.000000000000000 0.000000000000000 17.260000228900001
Atoms.UnitVectors>

#
# SCF or Electronic System
#
scf.electric.field 0.0 0.0 0.0 # default=0.0
scf.XcType GGA-PBE # LDA|LSDA-CA|LSDA-PW|GGA-PBE
scf.SpinPolarization NC # On|Off|NC
scf.ElectronicTemperature 300 # default=300 (K)
scf.energycutoff 300 # default=150 (Ry)
scf.maxIter 300 # default=40
scf.EigenvalueSolver band # DC|GDC|Cluster|Band
scf.Kgrid 16 16 1 # means n1 x n2 x n3
scf.Mixing.Type rmm-diish # Simple|Rmm-Diis|Gr-Pulay|Kerker|Rmm-Diisk
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 40 # default=5
scf.Mixing.StartPulay 30 # default=6
scf.criterion 1.0e-8 # default=1.0e-6 (Hartree)
scf.spinorbit.coupling off

#
# MD or Geometry Optimization
#
MD.Type Nomd # Nomd|Opt|NVE|NVT_VS|NVT_NH
MD.maxIter 30 # default=1
MD.Opt.DIIS.History 3O
MD.Opt.StartDIIS 5
MD.Opt.EveryDIIS 200
#MD.TimeStep 1 # default=0.5 (fs)
MD.Opt.criterion 1.0e-4 # default=1.0e-4 (Hartree/bohr)

<MD.Fixed.XYZ
1 1 1 1
2 0 0 0
3 0 0 0
MD.Fixed.XYZ>

#
# Band dispersion
#
Band.dispersion on # on|off, default=off
# if <Band.KPath.UnitCell does not exist,
# the reciprical lattice vector is employed.
Band.Nkpath 3
<Band.kpath
200 0.5 0.0 0.0 0.0 0.0 0.0 M g
200 0.0 0.0 0.0 0.67777 -0.33333 0.0 g K
200 0.677777 -0.33333 0.0 0.5 0.0 0.0 K M
Band.kpath>

### non-collinear NiBr2 monolayer with SOC effect and without electric field
#
# Definition of Atomic Species
#
Species.Number 2
<Definition.of.Atomic.Species
Br Br7.0-s3p3d2 Br_PBE19
Ni Ni6.0S-s3p3d2f1 Ni_PBE19S
Definition.of.Atomic.Species>

#
# Atoms
#
Atoms.Number 3
Atoms.SpeciesAndCoordinates.Unit FRAC # Ang|AU
<Atoms.SpeciesAndCoordinates
1 Ni 0.00000000000000 0.00000000000000 0.00000000000000 10.0 6.0 0.0 0.0 0.0 0.0 0 off
2 Br 0.33364644113299 0.66610406570644 0.08017052963226 3.5 3.5 0.0 0.0 0.0 0.0 0 off
3 Br 0.66635356275338 0.33389594190917 0.91982946734286 3.5 3.5 0.0 0.0 0.0 0.0 0 off
Atoms.SpeciesAndCoordinates>

Atoms.UnitVectors.Unit Ang
<Atoms.UnitVectors
3.700000000000000 0.000000000000000 0.000000000000000
-1.850000000000000 3.204294000000000 0.000000000000000
0.000000000000000 0.000000000000000 17.260000228900001
Atoms.UnitVectors>

#
# SCF or Electronic System
#
scf.electric.field 0.0 0.0 0.0 # default=0.0
scf.XcType GGA-PBE # LDA|LSDA-CA|LSDA-PW|GGA-PBE
scf.SpinPolarization NC # On|Off|NC
scf.ElectronicTemperature 300 # default=300 (K)
scf.energycutoff 300 # default=150 (Ry)
scf.maxIter 300 # default=40
scf.EigenvalueSolver band # DC|GDC|Cluster|Band
scf.Kgrid 16 16 1 # means n1 x n2 x n3
scf.Mixing.Type rmm-diish # Simple|Rmm-Diis|Gr-Pulay|Kerker|Rmm-Diisk
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 40 # default=5
scf.Mixing.StartPulay 30 # default=6
scf.criterion 1.0e-8 # default=1.0e-6 (Hartree)
scf.spinorbit.coupling on
scf.restart on # on|off,default=off

#
# MD or Geometry Optimization
#
MD.Type Nomd # Nomd|Opt|NVE|NVT_VS|NVT_NH
MD.maxIter 30 # default=1
MD.Opt.DIIS.History 3O
MD.Opt.StartDIIS 5
MD.Opt.EveryDIIS 200
#MD.TimeStep 1 # default=0.5 (fs)
MD.Opt.criterion 1.0e-4 # default=1.0e-4 (Hartree/bohr)

<MD.Fixed.XYZ
1 1 1 1
2 0 0 0
3 0 0 0
MD.Fixed.XYZ>

#
# Band dispersion
#
Band.dispersion on # on|off, default=off
# if <Band.KPath.UnitCell does not exist,
# the reciprical lattice vector is employed.
Band.Nkpath 3
<Band.kpath
200 0.5 0.0 0.0 0.0 0.0 0.0 M g
200 0.0 0.0 0.0 0.67777 -0.33333 0.0 g K
200 0.677777 -0.33333 0.0 0.5 0.0 0.0 K M
Band.kpath>

### non-collinear NiBr2 monolayer with 25 GV/m electric field and without SOC effect
#
# Definition of Atomic Species
#
Species.Number 2
<Definition.of.Atomic.Species
Br Br7.0-s3p3d2 Br_PBE19
Ni Ni6.0S-s3p3d2f1 Ni_PBE19S
Definition.of.Atomic.Species>

#
# Atoms
#
Atoms.Number 3
Atoms.SpeciesAndCoordinates.Unit FRAC # Ang|AU
<Atoms.SpeciesAndCoordinates
1 Ni 0.00000000000000 0.00000000000000 0.00000000000000 10.0 6.0 0.0 0.0 0.0 0.0 0 off
2 Br 0.33364644113299 0.66610406570644 0.08017052963226 3.5 3.5 0.0 0.0 0.0 0.0 0 off
3 Br 0.66635356275338 0.33389594190917 0.91982946734286 3.5 3.5 0.0 0.0 0.0 0.0 0 off
Atoms.SpeciesAndCoordinates>

Atoms.UnitVectors.Unit Ang
<Atoms.UnitVectors
3.700000000000000 0.000000000000000 0.000000000000000
-1.850000000000000 3.204294000000000 0.000000000000000
0.000000000000000 0.000000000000000 17.260000228900001
Atoms.UnitVectors>

#
# SCF or Electronic System
#
scf.electric.field 0.0 0.0 25.0 # default=0.0
scf.XcType GGA-PBE # LDA|LSDA-CA|LSDA-PW|GGA-PBE
scf.SpinPolarization NC # On|Off|NC
scf.ElectronicTemperature 300 # default=300 (K)
scf.energycutoff 300 # default=150 (Ry)
scf.maxIter 300 # default=40
scf.EigenvalueSolver band # DC|GDC|Cluster|Band
scf.Kgrid 16 16 1 # means n1 x n2 x n3
scf.Mixing.Type rmm-diis # Simple|Rmm-Diis|Gr-Pulay|Kerker|Rmm-Diisk
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 40 # default=5
scf.Mixing.StartPulay 30 # default=6
scf.criterion 1.0e-8 # default=1.0e-6 (Hartree)
scf.spinorbit.coupling off

#
# MD or Geometry Optimization
#
MD.Type Nomd # Nomd|Opt|NVE|NVT_VS|NVT_NH
MD.maxIter 30 # default=1
MD.Opt.DIIS.History 3O
MD.Opt.StartDIIS 5
MD.Opt.EveryDIIS 200
#MD.TimeStep 1 # default=0.5 (fs)
MD.Opt.criterion 1.0e-4 # default=1.0e-4 (Hartree/bohr)

<MD.Fixed.XYZ
1 1 1 1
2 0 0 0
3 0 0 0
MD.Fixed.XYZ>

#
# Band dispersion
#
Band.dispersion on # on|off, default=off
# if <Band.KPath.UnitCell does not exist,
# the reciprical lattice vector is employed.
Band.Nkpath 3
<Band.kpath
200 0.5 0.0 0.0 0.0 0.0 0.0 M g
200 0.0 0.0 0.0 0.67777 -0.33333 0.0 g K
200 0.677777 -0.33333 0.0 0.5 0.0 0.0 K M
Band.kpath>

Thank you very much.

Best regards,

Bagus

Page: [1]

Re: Check symmetry breaking under influence of SOI and/or electric charge ( No.1 )

Date: 2022/03/26 14:16
Name: Naoya Yamaguchi

Hi,

>However, after doing the calculations, there is no change in atomic distance Ni-Br or atomic angle Ni-Br-Ni when I visualize the .xyz and .bulk.xyz output files on VESTA.

You set `MD.Type Nomd`, and therefore the atoms can't move.
I also mention that `scf.electric.field` doesn't seem to be compatible with the MD.

Regards,
Naoya Yamaguchi

Re: Check symmetry breaking under influence of SOI and/or electric charge ( No.2 )

Date: 2022/03/27 22:15
Name: Bagus <bagusnuryasin_3225160838@mhs.unj.ac.id>

Dear Naoya Yamaguchi,

I never realize `MD.Type Nomd` actually immobilizes the atoms which makes the structure frozen.

>I also mention that `scf.electric.field` doesn't seem to be compatible with the MD.

so to apply `scf.electric.field`, it need to be `MD.Type Nomd`.
Thank you very much for your advice. I'm glad you helped me get an answer.

Best regards,

Bagus

Page: [1]