Re: Band dispersion of the narrow-bandgap semiconductor black phosphorus ( No.1 ) |
- Date: 2022/07/06 21:12
- Name: Mehdi Vejdanihemmat <m.vejdanih@gmail.com>
- Dear Hiroaki,
Why don't you use DFT+U method? http://www.openmx-square.org/openmx_man3.9/node105.html
Best regards, Mehdi Vejdanihemmat
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Re: Band dispersion of the narrow-bandgap semiconductor black phosphorus ( No.2 ) |
- Date: 2022/07/08 09:56
- Name: Hiroaki Tanaka <hiroaki-tanaka@issp.u-tokyo.ac.jp>
- Dear Mehdi,
Thank you for your suggestion.
I already tried DFT+U method, but the result was the same. Since the system is spin-degenerated, I think DFT+U method does not affect the electronic structure.
Best regards, Hiroaki Tanaka
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Re: Band dispersion of the narrow-bandgap semiconductor black phosphorus ( No.3 ) |
- Date: 2022/07/26 14:42
- Name: T. Ozaki
- Hi,
I wondered how you detemined the band gap of your system, since the gap closing seems to occur at low symmetry points in the band dispersion.
On the other hands, using the structure optimized with the GGA-PBE, which was taken from Materiasl Project, I also performed the calculation, and got a band gap of ~0.1 eV at the Y-point, which is consistent with Materiasl Project. One way to have the band gap might be to use the structure optimized with the GGA-PBE, which has a bit longer lattice constants compared to experimental values.
For your reference, the following is the input file used for the calculation.
Regards,
TO
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System.CurrrentDirectory ./ System.Name phos level.of.stdout 1 level.of.fileout 1
Species.Number 1 <Definition.of.Atomic.Species P P7.0-s2p2d1f1 P_PBE19 Definition.of.Atomic.Species>
Atoms.Number 4 Atoms.SpeciesAndCoordinates.Unit Ang <Atoms.SpeciesAndCoordinates 1 P -0.5499100 1.8853336 4.1585565 2.5 2.5 2 P 1.4842878 1.2859913 0.3938615 2.5 2.5 3 P -3.8975295 2.8716537 1.8823475 2.5 2.5 4 P 4.8319073 0.2996712 2.6700705 2.5 2.5 Atoms.SpeciesAndCoordinates>
Atoms.UnitVectors.Unit Ang <Atoms.UnitVectors 5.8490062 0.0000000 0.0000000 -4.9146284 3.1713249 0.0000000 0.0000000 0.0000000 4.5524180 Atoms.UnitVectors>
scf.XcType GGA-PBE scf.SpinPolarization off scf.ElectronicTemperature 300.0 scf.energycutoff 220.0 scf.maxIter 100 scf.EigenvalueSolver band scf.Kgrid 12 12 8 scf.Mixing.Type rmm-diisk scf.Init.Mixing.Weight 0.05 scf.Min.Mixing.Weight 0.01 scf.Max.Mixing.Weight 0.30 scf.Mixing.History 25 scf.Mixing.StartPulay 15 scf.criterion 1.0e-7
MD.Type nomd MD.maxIter 1 MD.TimeStep 1.0 MD.Opt.criterion 0.0003
Band.dispersion on # on|off, default=off Band.Nkpath 9 <Band.kpath 45 0.2750173044 0.2750173044 0.5000000000 -0.2750173044 0.7249826956 0.0000000000 A0 C0 45 -0.2750173044 0.7249826956 0.0000000000 -0.2750173044 0.7249826956 0.5000000000 C0 E0 45 -0.2750173044 0.7249826956 0.5000000000 0.0000000000 0.0000000000 0.0000000000 E0 G 45 0.0000000000 0.0000000000 0.0000000000 0.0000000000 0.5000000000 0.5000000000 G R 45 0.0000000000 0.5000000000 0.5000000000 0.0000000000 0.5000000000 0.0000000000 R S 45 0.0000000000 0.5000000000 0.0000000000 0.2750173044 0.2750173044 0.0000000000 S Sigma0 45 0.2750173044 0.2750173044 0.0000000000 -0.5000000000 0.5000000000 0.5000000000 Sigma0 T 45 -0.5000000000 0.5000000000 0.5000000000 -0.5000000000 0.5000000000 0.0000000000 T Y 45 -0.5000000000 0.5000000000 0.0000000000 0.0000000000 0.0000000000 0.5000000000 Y Z Band.kpath>
Dos.fileout on Dos.Erange -8.0 8.0 Dos.Kgrid 24 24 16
![メンテ](./img/mente.gif) |
Re: Band dispersion of the narrow-bandgap semiconductor black phosphorus ( No.4 ) |
- Date: 2022/07/29 22:14
- Name: Hiroaki Tanaka <hiroaki-tanaka@issp.u-tokyo.ac.jp>
- Dear Prof. Ozaki,
I could reproduce small bandgap using the unit cell presented above. Thank you for your advice!
Best regards, Hiroaki Tanaka
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