The only thing that is evident to me at this moment is that you are avoiding the K-points in your k-point sampling; as indicated by Marco Verisimo a number of years ago your number of k-points must be a multiple of three, which it is, but the shift by 0.5, 0.5 is driving the sampling away from the K-points and avoiding them... Hopefully bringing the shifts to 0.0 0.0 0.0 solves the "differential," or the missing of the K-point on the conduction band.
I would work on the Mo pseudo a little more; and have you checked the effect of the basis size as well? Do your pseudos give you a reasonable bulk band structure? Best regards, -Salvador ________________________________ From: [email protected] <[email protected]> on behalf of Xiaoming Wang <[email protected]> Sent: Thursday, April 30, 2015 7:23 PM To: [email protected] Subject: [SIESTA-L] Band structure of MoSe2 Dear Siesta users, Recently, I’m trying to calculate the band structure of monolayer MoSe2. However, when I plotting the bands, the band curves at K point are not at maximum or minimum, which should be. And there seems a non-differential point at K along the bands. The band structure of MoSe2 is attached, the non-differential point is more obvious at the lowest two bands shown in the Fig. Both LDA and PBE functionals give this strange phenomenon. I have tried to tune many parameters, but failed to get good result. Can anyone help me with the problem? By the way, I have tried pseudopotentials from Siesta website and from http://charter.cnf.cornell.edu/<https://urldefense.proofpoint.com/v2/url?u=http-3A__charter.cnf.cornell.edu_&d=AwMFAg&c=JL-fUnQvtjNLb7dA39cQUcqmjBVITE8MbOdX7Lx6ge8&r=n_Y76F1vumEs9EYNHN2gzA5FD9jzyPhrzl3eOzxCHIQ&m=NaDRSvcZImjiuqSJSGFoSEOGLfumFBd6_fRZa0Hs0Bs&s=UQq2ZNZfUJL5kmP2F3B0GlcPmhnT4dJuFcGi_NHsl2Q&e=>, and also used the recently published pps of Comput. Mater. Sci. , 98 (2015) 372-389. I also changed the energshift, meshcutoff, and k point mesh. But none of them can resolve the problem. Below are the input files for relaxation and band structure calculations. Any comment or advice are highly appreciated. fdf for relaxation: # General System Descriptors SystemName mose2 SystemLabel mose2 NumberOfAtoms 3 NumberOfSpecies 2 %block ChemicalSpeciesLabel 1 42 Mo 2 34 Se %endblock ChemicalSpeciesLabel PAO.EnergyShift 50 meV PAO.BasisSize DZP # Structure and K-sampling LatticeConstant 1.00 Ang %block LatticeParameters 3.25 3.25 20.00 90. 90. 120. %endblock LatticeParameters AtomicCoordinatesFormat Fractional AtomicCoorFormatOut Ang %block AtomicCoordinatesAndAtomicSpecies 0.333333333 0.666666670 0.505669950 1 0.666666667 0.333333330 0.625537344 2 0.666666667 0.333333330 0.385811946 2 %endblock AtomicCoordinatesAndAtomicSpecies %block kgrid_Monkhorst_Pack 12 0 0 0.5 0 12 0 0.5 0 0 1 0.0 %endblock kgrid_Monkhorst_Pack # DFT XC.functional LDA XC.authors CA SpinPolarized false MaxSCFIterations 200 DM.MixingWeight 0.25 DM.NumberPulay 3 DM.Tolerance 1.d-5 MeshCutoff 300 Ry SolutionMethod diagon ElectronicTemperature 300.0 K # MD and Relaxations MD.TypeOfRun CG MD.VariableCell T MD.MaxForceTol 0.01 eV/Ang MD.MaxStressTol 0.1 GPa MD.NumCGsteps 200 MD.MaxCGDispl 0.1 Ang MD.RelaxCellOnly F %block GeometryConstraints stress 3 4 5 6 %endblock GeometryConstraints # Output options WriteCoorInitial true WriteCoorStep true WriteForces true WriteKpoints false WriteEigenvalues false WriteKbands false WriteBands false WriteMullikenPop 0 WriteWaveFunction false WriteCoorXmol true WriteCoorCerius false WriteMDCoorXmol true WriteMDhistory true WriteMDXmol true WriteDM true fdf for band structure: # General System Descriptors SystemName mose2 SystemLabel mose2 NumberOfAtoms 3 NumberOfSpecies 2 %block ChemicalSpeciesLabel 1 42 Mo 2 34 Se %endblock ChemicalSpeciesLabel PAO.BasisSize DZP PAO.EnergyShift 50 meV # Structure and K-sampling LatticeConstant 1.00 Ang %block LatticeParameters 3.16 3.16 13.00 90. 90. 120. %endblock LatticeParameters AtomicCoordinatesFormat Fractional AtomicCoorFormatOut Ang %block AtomicCoordinatesAndAtomicSpecies 0.333333333 0.666666670 0.505669950 1 0.666666667 0.333333330 0.625537344 2 0.666666667 0.333333330 0.385811946 2 %endblock AtomicCoordinatesAndAtomicSpecies %block kgrid_Monkhorst_Pack 24 0 0 0.5 0 24 0 0.5 0 0 1 0.0 %endblock kgrid_Monkhorst_Pack # DFT XC.functional LDA XC.authors CA SpinPolarized false MaxSCFIterations 200 DM.MixingWeight 0.25 DM.NumberPulay 3 DM.Tolerance 1.d-5 MeshCutoff 300 Ry SolutionMethod diagon ElectronicTemperature 300.0 K # Output options WriteCoorInitial true WriteCoorStep true WriteForces true WriteKpoints false WriteEigenvalues false WriteKbands false WriteBands false WriteMullikenPop 0 WriteWaveFunction false WriteCoorXmol true WriteCoorCerius false WriteMDCoorXmol true WriteMDhistory true WriteMDXmol true WriteDM true UseStructFile T BandLinesScale ReciprocalLatticeVectors %block BandLines 1 0.0000 0.0000 0.0000 \Gamma 70 0.0000 0.5000 0.0000 M 40 0.3333 0.3333 0.0000 K 80 0.0000 0.0000 0.0000 \Gamma %endblock BandLines Best regards, Xiaoming Wang IAMDN, Rutgers
