Re: bandstructure problem ( No.1 ) |
- Date: 2015/03/11 14:36
- Name: Mosahar <mosahar_bagheri@yahoo.com>
- Sorry, I get horizental lines.
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Re: bandstructure problem ( No.2 ) |
- Date: 2015/03/11 16:26
- Name: Seungjin
- I think your Band.KPath.Unitcell has to be
<Band.KPath.UnitCell 24.286764 0.000000 0.000000 0.000000 17.843337 0.000000 0.000000 0.000000 17.843337 Band.KPath.UnitCell>
and Band.kpath has to represeted in fractional coordinate, something like 7 0.0 0.0 0.0 0.0 0.5 0.0 g X
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Re: bandstructure problem ( No.3 ) |
- Date: 2015/03/11 18:52
- Name: Artem Pulkin <artem.pulkin@epfl.ch>
- Hi,
As far as I understood you have vacuum in y and z directions. There is no dispersion there. Also, 7 points per path segment is way too small. Try
<Band.kpath 100 -0.5 0 0 0.5 0 0 X X Band.kpath>
Artem
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Re: bandstructure problem ( No.4 ) |
- Date: 2015/03/12 07:13
- Name: Mosahar <mosahar_bagheri@yahoo.com>
- Hi,
I applied both suggestions but result is the same. Infact, I used supercell proposed by the code. any help?
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Re: bandstructure problem ( No.5 ) |
- Date: 2015/03/12 18:40
- Name: Artem Pulkin <artem.pulkin@epfl.ch>
- Ok, I plotted your input file and I see that you have a hydrogenated nanotube particle. The horizontal lines indeed is your band structure: there should be no dispersion at all. In other words you have energy levels corresponding to localized molecular states in your system. Therefore there is nothing wrong with OpenMX.
It is also pointless to have
scf.Kgrid 4 4 4
Instead, use a Gamma-point calculation for molecules = clusters (diagonalization should be faster ~64 times)
scf.Kgrid 1 1 1
But first you should really think about what results did you expect and why.
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Re: bandstructure problem ( No.6 ) |
- Date: 2015/03/13 15:18
- Name: Mosahar <mosahar_bagheri@yahoo.com>
- Hi
In fact, for warming up, I followed the following article: X. Blase, A. Rubio, S.G. Louie, M. L. Cohen, Europhys. Lett. 28 (1994) 335. In this paper, authors have presented a band structure for boron nitride nanotubes and I'm trying to get that structure using supercell approach but so far no success. Would you share your experience? Thank you in advance
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Re: bandstructure problem ( No.7 ) |
- Date: 2015/03/13 17:19
- Name: T. Ozaki
- Hi,
An isolated system does not have the band dispersion, but discretized eigenvalues. Thus, your hydrogen terminated BN nanotube does not have the band dispersion as you obtained.
Regards,
TO
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Re: bandstructure problem ( No.8 ) |
- Date: 2015/03/18 05:04
- Name: Mosahar <mosahar_bagheri@yahoo.com>
- Hi,
Thank you dear professor Ozaki. I have modified the input BNNT structure and removed hydrogens. When I run input file for geometry optimization, scf converges but after some progress in MD, total energy and maximum force begin oscillation:
*********************************************************** *********************************************************** History of geometry optimization *********************************************************** ***********************************************************
MD_iter SD_scaling |Maximum force| Maximum step Utot (Hartree/Bohr) (Ang) (Hartree)
1 0.94486299 0.04056948 0.02028474 -522.97598501 2 0.94486299 0.02781796 0.01390898 -523.01951509 3 0.94486299 0.02645365 0.01322683 -523.03793728 4 0.94486299 0.02637596 0.01318798 -523.05219980 5 2.36215748 0.02649247 0.03175063 -523.06478235 6 2.36215748 0.02670056 0.01412933 -523.09213420 7 2.36215748 0.02687571 0.03175063 -523.10338575 8 2.36215748 0.02722117 0.03175063 -523.12833492 9 2.36215748 0.02749532 0.03175063 -523.15309442 10 2.36215748 0.02764184 0.03175063 -523.17773589 11 2.36215748 0.02763336 0.03175063 -523.20229615 12 2.36215748 0.02749699 0.03175063 -523.22682483 13 2.36215748 0.02725463 0.03175063 -523.25134856 14 2.36215748 0.02686756 0.03175063 -523.27577700 15 2.36215748 0.02635634 0.03175063 -523.30012601 16 2.36215748 0.02584265 0.03175063 -523.32469256 17 2.36215748 0.02519697 0.03175063 -523.34922229 18 2.36215748 0.02443732 0.03175063 -523.37378455 19 2.36215748 0.02366707 0.03175063 -523.39868542 20 2.36215748 0.02274703 0.03175063 -523.42358740 21 2.36215748 0.02169172 0.03175063 -523.44854263 22 2.36215748 0.02143571 0.03175063 -523.47406615 23 2.36215748 0.02161840 0.03175063 -523.50057814 24 2.36215748 0.02230131 0.03175063 -523.52856785 25 2.36215748 0.02297869 0.03175063 -523.55711710 26 2.36215748 0.02363848 0.03175063 -523.58582055 27 2.36215748 0.02418903 0.03175063 -523.61495216 28 2.36215748 0.02421663 0.03175063 -523.64352781 29 2.36215748 0.02393648 0.03175063 -523.67130122 30 2.36215748 0.02455878 0.03175063 -523.69815324 31 2.36215748 0.02631866 0.03175063 -523.72436075 32 2.36215748 0.02691485 0.03175063 -523.75030171 33 2.36215748 0.02706976 0.03175063 -523.77568533 34 2.36215748 0.02812129 0.03175063 -523.80018491 35 2.36215748 0.02977074 0.03175063 -523.82419170 36 2.36215748 0.03115271 0.03175063 -523.84812342 37 2.36215748 0.03205754 0.03175063 -523.87189799 38 2.36215748 0.03293699 0.03175063 -523.89521516 39 2.36215748 0.03563253 0.03175063 -523.91809065 40 2.36215748 0.03190626 0.03175063 -523.89356372 41 2.36215748 0.02978836 0.03175063 -523.86902549 42 2.36215748 0.02765527 0.03175063 -523.84634717 43 2.36215748 0.02474379 0.03175063 -523.82543705 44 2.36215748 0.02206598 0.03175063 -523.80547468 45 2.36215748 0.02164719 0.03175063 -523.78607450 46 2.36215748 0.02235303 0.03175063 -523.76721431 47 2.36215748 0.02307703 0.03175063 -523.74897024 48 2.36215748 0.02644688 0.03175063 -523.73102955 49 2.36215748 0.03162899 0.03175063 -523.71324594
I don't know what is wrong! My input file is as follows:
# # File Name #
System.CurrrentDirectory ./ # default=./ System.Name BN100 level.of.stdout 1 # default=1 (1-3) level.of.fileout 1 # default=1 (0-2)
# # Definition of Atomic Species #
Species.Number 2 <Definition.of.Atomic.Species N N7.0-s2p2d1 N_PBE13 B B7.0-s2p2d1 B_PBE13 Definition.of.Atomic.Species>
# # Atoms #
Atoms.Number 80 Atoms.SpeciesAndCoordinates.Unit Ang # Ang|AU <Atoms.SpeciesAndCoordinates 1 N 4.00948 0.000 -2.90448 2.5 2.5 2 B 4.00948 0.000 -4.35448 1.5 1.5 3 N 3.81324 1.239 -0.72724 2.5 2.5 4 B 3.81324 1.239 -2.17724 1.5 1.5 5 N 3.24374 2.35671 -2.90448 2.5 2.5 6 B 3.24374 2.35671 -4.35448 1.5 1.5 7 N 2.35671 3.24374 -0.72724 2.5 2.5 8 B 2.35671 3.24374 -2.17724 1.5 1.5 9 N 1.239 3.81324 -2.90448 2.5 2.5 10 B 1.239 3.81324 -4.35448 1.5 1.5 11 N 0.000 4.00948 -0.72724 2.5 2.5 12 B 0.000 4.00948 -2.17724 1.5 1.5 13 N -1.239 3.81324 -2.90448 2.5 2.5 14 B -1.239 3.81324 -4.35448 1.5 1.5 15 N -2.35671 3.24374 -0.72724 2.5 2.5 16 B -2.35671 3.24374 -2.17724 1.5 1.5 17 N -3.24374 2.35671 -2.90448 2.5 2.5 18 B -3.24374 2.35671 -4.35448 1.5 1.5 19 N -3.81324 1.239 -0.72724 2.5 2.5 20 B -3.81324 1.239 -2.17724 1.5 1.5 21 N -4.00948 0.000 -2.90448 2.5 2.5 22 B -4.00948 0.000 -4.35448 1.5 1.5 23 N -3.81324 -1.239 -0.72724 2.5 2.5 24 B -3.81324 -1.239 -2.17724 1.5 1.5 25 N -3.24374 -2.35671 -2.90448 2.5 2.5 26 B -3.24374 -2.35671 -4.35448 1.5 1.5 27 N -2.35671 -3.24374 -0.72724 2.5 2.5 28 B -2.35671 -3.24374 -2.17724 1.5 1.5 29 N -1.239 -3.81324 -2.90448 2.5 2.5 30 B -1.239 -3.81324 -4.35448 1.5 1.5 31 N 0.000 -4.00948 -0.72724 2.5 2.5 32 B 0.000 -4.00948 -2.17724 1.5 1.5 33 N 1.239 -3.81324 -2.90448 2.5 2.5 34 B 1.239 -3.81324 -4.35448 1.5 1.5 35 N 2.35671 -3.24374 -0.72724 2.5 2.5 36 B 2.35671 -3.24374 -2.17724 1.5 1.5 37 N 3.24374 -2.35671 -2.90448 2.5 2.5 38 B 3.24374 -2.35671 -4.35448 1.5 1.5 39 N 3.81324 -1.239 -0.72724 2.5 2.5 40 B 3.81324 -1.239 -2.17724 1.5 1.5 41 N 4.00948 0.000 1.45 2.5 2.5 42 B 4.00948 0.000 0.000 1.5 1.5 43 N 3.81324 1.239 3.62724 2.5 2.5 44 B 3.81324 1.239 2.17724 1.5 1.5 45 N 3.24374 2.35671 1.45 2.5 2.5 46 B 3.24374 2.35671 0.000 1.5 1.5 47 N 2.35671 3.24374 3.62724 2.5 2.5 48 B 2.35671 3.24374 2.17724 1.5 1.5 49 N 1.239 3.81324 1.45 2.5 2.5 50 B 1.239 3.81324 0.000 1.5 1.5 51 N 0.000 4.00948 3.62724 2.5 2.5 52 B 0.000 4.00948 2.17724 1.5 1.5 53 N -1.239 3.81324 1.45 2.5 2.5 54 B -1.239 3.81324 0.000 1.5 1.5 55 N -2.35671 3.24374 3.62724 2.5 2.5 56 B -2.35671 3.24374 2.17724 1.5 1.5 57 N -3.24374 2.35671 1.45 2.5 2.5 58 B -3.24374 2.35671 0.000 1.5 1.5 59 N -3.81324 1.239 3.62724 2.5 2.5 60 B -3.81324 1.239 2.17724 1.5 1.5 61 N -4.00948 0.000 1.45 2.5 2.5 62 B -4.00948 0.000 0.000 1.5 1.5 63 N -3.81324 -1.239 3.62724 2.5 2.5 64 B -3.81324 -1.239 2.17724 1.5 1.5 65 N -3.24374 -2.35671 1.45 2.5 2.5 66 B -3.24374 -2.35671 0.000 1.5 1.5 67 N -2.35671 -3.24374 3.62724 2.5 2.5 68 B -2.35671 -3.24374 2.17724 1.5 1.5 69 N -1.239 -3.81324 1.45 2.5 2.5 70 B -1.239 -3.81324 0.000 1.5 1.5 71 N 0.000 -4.00948 3.62724 2.5 2.5 72 B 0.000 -4.00948 2.17724 1.5 1.5 73 N 1.239 -3.81324 1.45 2.5 2.5 74 B 1.239 -3.81324 0.000 1.5 1.5 75 N 2.35671 -3.24374 3.62724 2.5 2.5 76 B 2.35671 -3.24374 2.17724 1.5 1.5 77 N 3.24374 -2.35671 1.45 2.5 2.5 78 B 3.24374 -2.35671 0.000 1.5 1.5 79 N 3.81324 -1.239 3.62724 2.5 2.5 80 B 3.81324 -1.239 2.17724 1.5 1.5 Atoms.SpeciesAndCoordinates> Atoms.UnitVectors.Unit Ang # Ang|AU <Atoms.UnitVectors 20.0 0.0 0.0 0.0 20.0 0.0 0.0 0.0 20.0 Atoms.UnitVectors>
# # SCF or Electronic System #
scf.XcType GGA-PBE # LDA|LSDA-CA|LSDA-PW scf.SpinPolarization off # On|Off scf.ElectronicTemperature 300.0 # default=300 (K) scf.energycutoff 180.0 # default=150 (Ry) scf.maxIter 200 # default=40 scf.EigenvalueSolver Band # Recursion|Cluster|Band scf.lapack.dste dstevx # dstevx|dstedc|dstegr,default=dstegr scf.Kgrid 3 3 3 # means 4x4x4 scf.Mixing.Type rmm-diis # Simple|Rmm-Diis|Gr-Pulay scf.Init.Mixing.Weight 0.05 # default=0.30 scf.Min.Mixing.Weight 0.001 # default=0.001 scf.Max.Mixing.Weight 0.100 # default=0.40 scf.Mixing.History 30 # default=5 scf.Mixing.StartPulay 10 # default=6 scf.criterion 1.0e-8 # default=1.0e-6 (Hartree)
# # MD or Geometry Optimization #
MD.Type BFGS # Nomd|Opt|DIIS|NVE|NVT_VS|NVT_NH MD.Opt.DIIS.History 3 # default=4 MD.Opt.StartDIIS 6 # default=5 MD.Opt.EveryDIIS 10000 # default=10 MD.maxIter 200 # default=1xsx MD.TimeStep 1.0 # default=0.5 (fs) MD.Opt.criterion 1.0e-4 # default=1.0e-4 (Hartree/bohr)
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Re: bandstructure problem ( No.9 ) |
- Date: 2015/03/18 19:57
- Name: Artem Pulkin <artem.pulkin@epfl.ch>
- From my experience, BFGS optimization performs poorly in OpenMX (I used it for spin-resolved calculations, though). Steepest descent is often an option but it needs a lot more iterations to converge. As far as I know there is also a keyword in OpenMX to combine BFGS and SD, see documentation.
Also scf.energycutoff 180.0 is way too small for geometry optimization in localized basis set codes. It should not affect convergence, though (you will just get a wrong structure/energy).
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Re: bandstructure problem ( No.10 ) |
- Date: 2015/03/18 23:18
- Name: Mosahar <mosahar_bagheri@yahoo.com>
- Hi,
Dear Artem thank you for tips. When hydrogens are added, this setup works perfect but when hydrogens are removed (existence of dangling bonds) oscillations occure.
Best regards
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Re: bandstructure problem ( No.11 ) |
- Date: 2015/03/25 20:59
- Name: Mosahar <mosahar_bagheri@yahoo.com>
- Hi,
Thank you all for helpful comments. I finally solved the problem. Mosahar
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