Your electrode length is almost certainly too small, you must ensure
principal cell connections, only. Try and double your electrode.

--

Kind regards Nick Papior
On 30 Oct 2015 00:54, "Damien Tristant" <[email protected]> wrote:

> Dear Everybody
>
> I am trying to obtain the transmission spectrum of a metallic carbon
> nanotube (8,8), carried out with Transiesta code. Unfortunately I don’t get
> the right spectrum (normally at the Fermi level I should see two conduction
> channels appear, I have attached the file).  I have changed the settings
> several times but the result is never correct. In the following there is my
> input files for the electrodes and the scattering zone.
> Could you please check if one of my parameters is wrong or if I forgot
> something?
> Thank you very much for your help.
> Best regards.
>
> Damien
>
>
> *Electrode :*
>
>
> # General system descriptors
> SystemName              cnt
> SystemLabel             cnt
> NumberOfAtoms           32
> NumberOfSpecies         1
>
> %block ChemicalSpeciesLabel
>  1  6 C.gga   # Species index, atomic number, species label
> %endblock ChemicalSpeciesLabel
>
> #Unit cell for the calculation
> LatticeConstant 1 Ang
> %block LatticeVectors
> 30.0000000000000000  0.0000000000000000  0.0000000000000000
>  0.0000000000000000 30.0000000000000000  0.0000000000000000
>  0.0000000000000000  0.0000000000000000  2.4617000000000000
> %endblock LatticeVectors
>
> # Lattice, coordinates, k-sampling
>
> AtomicCoordinatesFormat Fractional
> AtomicCoorFormatOut     Fractional
>
> %block AtomicCoordinatesAndAtomicSpecies
>  0.684228479       0.500102328      -0.000000000 1
>  0.677959183       0.547673034       0.000000000 1
>  0.670191861       0.570611130       0.500000000 1
>  0.646198057       0.612161657       0.500000000 1
>  0.630219773       0.630352389       0.000000000 1
>  0.592119446       0.659511823      -0.000000000 1
>  0.570405934       0.670221335       0.500000000 1
>  0.524063557       0.682647265       0.500000001 1
>  0.499897672       0.684228479      -0.000000000 1
>  0.452326966       0.677959184      -0.000000000 1
>  0.429388870       0.670191860       0.500000000 1
>  0.387838343       0.646198057       0.500000000 1
>  0.369647610       0.630219773       0.000000000 1
>  0.340488177       0.592119446      -0.000000000 1
>  0.329778665       0.570405934       0.500000000 1
>  0.317352735       0.524063557       0.500000000 1
>  0.315771521       0.499897672       0.000000000 1
>  0.322040816       0.452326966      -0.000000000 1
>  0.329808140       0.429388870       0.500000000 1
>  0.353801943       0.387838343       0.500000000 1
>  0.369780227       0.369647611      -0.000000000 1
>  0.407880554       0.340488177       0.000000000 1
>  0.429594066       0.329778665       0.499999999 1
>  0.475936443       0.317352735       0.500000001 1
>  0.500102328       0.315771521      -0.000000000 1
>  0.547673034       0.322040816      -0.000000000 1
>  0.570611130       0.329808139       0.500000001 1
>  0.612161657       0.353801943       0.500000000 1
>  0.630352390       0.369780227      -0.000000000 1
>  0.659511823       0.407880554      -0.000000000 1
>  0.670221335       0.429594066       0.500000000 1
>  0.682647265       0.475936443       0.500000000 1
> %endblock AtomicCoordinatesAndAtomicSpecies
>
> # K-sampling (alternative specification using kgrid_cutoff)
> %block kgrid_Monkhorst_Pack
>  1   0   0   0.0
>  0   1   0   0.0
>  0   0   100 0.0
> %endblock kgrid_Monkhorst_Pack
>
> # Basis set definition
> PAO.BasisSize   DZP
> PAO.EnergyShift 50 meV
> PAO.SplitNorm   0.15
>
> # Real space grid
> MeshCutoff 200.0 Ry
>
> #Convergence of SCF
> MaxSCFIterations 100
> DM.MixingWeight  0.05
> DM.NumberPulay   10
> DM.Tolerance     0.0001
>
> # Eigenvalue problem: order-N or diagonalization
> SolutionMethod          diagon
> ElectronicTemperature   5.0 K
>
>
> # Density functional (Notice that Xc.authors and XC.functional)
> XC.functional           VDW
> XC.authors              KBM
>
> # Molecular Dynamics and relaxations
> MD.TypeOfRun            CG
> MD.NumCGsteps           0
> MD.VariableCell         .false.
> MD.ConstantVolume       .true.
>
> # Output options
> WriteCoorInitial        .false.
> WriteCoorStep           .true.
> WriteForces             .false.
> WriteKpoints            .false.
> WriteEigenvalues        .false.
> WriteDM                 .true.
> WriteKbands             .false.
> WriteBands              .false.
> WriteWaveFunctions      .true.
> WriteMullikenPop        0
> WriteCoorXmol           .true.
> WriteCoorCerius         .true.
> WriteMDXmol             .true.
> WriteMDhistory          .true.
>
> *Scattering zone :*
>
> # General system descriptors
> SystemName              cnt-system
> SystemLabel             cnt-system
> NumberOfAtoms           96
> NumberOfSpecies         1
>
> %block ChemicalSpeciesLabel
>  1  6 C.gga   # Species index, atomic number, species label
> %endblock ChemicalSpeciesLabel
>
> #Unit cell for the calculation
> LatticeConstant 1 Ang
> %block LatticeVectors
> 30.0000000000000000  0.0000000000000000  0.0000000000000000
>  0.0000000000000000 30.0000000000000000  0.0000000000000000
>  0.0000000000000000  0.0000000000000000  7.3851000000000000
> %endblock LatticeVectors
>
> # Lattice, coordinates, k-sampling
>
> AtomicCoordinatesFormat Fractional
> AtomicCoorFormatOut     Fractional
>
> %block AtomicCoordinatesAndAtomicSpecies
>   0.6842284789999999  0.5001023280000000  0.0000000000000000 1
>   0.6779591830000000  0.5476730340000000  0.0000000000000000 1
>   0.6701918610000001  0.5706111300000000  0.1666666666666667 1
>   0.6461980570000000  0.6121616570000000  0.1666666666666667 1
>   0.6302197730000000  0.6303523890000000  0.0000000000000000 1
>   0.5921194460000000  0.6595118230000000  0.0000000000000000 1
>   0.5704059339999999  0.6702213350000000  0.1666666666666667 1
>   0.5240635570000000  0.6826472649999999  0.1666666670000000 1
>   0.4998976720000000  0.6842284789999999  0.0000000000000000 1
>   0.4523269660000000  0.6779591840000000  0.0000000000000000 1
>   0.4293888700000000  0.6701918600000000  0.1666666666666667 1
>   0.3878383430000000  0.6461980570000000  0.1666666666666667 1
>   0.3696476100000000  0.6302197730000000  0.0000000000000000 1
>   0.3404881770000000  0.5921194460000000  0.0000000000000000 1
>   0.3297786650000000  0.5704059339999999  0.1666666666666667 1
>   0.3173527350000000  0.5240635570000000  0.1666666666666667 1
>   0.3157715210000000  0.4998976720000000  0.0000000000000000 1
>   0.3220408160000000  0.4523269660000000  0.0000000000000000 1
>   0.3298081400000000  0.4293888700000000  0.1666666666666667 1
>   0.3538019430000000  0.3878383430000000  0.1666666666666667 1
>   0.3697802270000000  0.3696476110000000  0.0000000000000000 1
>   0.4078805540000000  0.3404881770000000  0.0000000000000000 1
>   0.4295940660000000  0.3297786650000000  0.1666666663333333 1
>   0.4759364430000000  0.3173527350000000  0.1666666670000000 1
>   0.5001023280000000  0.3157715210000000  0.0000000000000000 1
>   0.5476730340000000  0.3220408160000000  0.0000000000000000 1
>   0.5706111300000000  0.3298081390000000  0.1666666670000000 1
>   0.6121616570000000  0.3538019430000000  0.1666666666666667 1
>   0.6303523900000000  0.3697802270000000  0.0000000000000000 1
>   0.6595118230000000  0.4078805540000000  0.0000000000000000 1
>   0.6702213350000000  0.4295940660000000  0.1666666666666667 1
>   0.6826472649999999  0.4759364430000000  0.1666666666666667 1
>   0.6842284789999999  0.5001023280000000  0.3333333333333333 1
>   0.6779591830000000  0.5476730340000000  0.3333333333333333 1
>   0.6701918610000001  0.5706111300000000  0.5000000000000000 1
>   0.6461980570000000  0.6121616570000000  0.5000000000000000 1
>   0.6302197730000000  0.6303523890000000  0.3333333333333333 1
>   0.5921194460000000  0.6595118230000000  0.3333333333333333 1
>   0.5704059339999999  0.6702213350000000  0.5000000000000000 1
>   0.5240635570000000  0.6826472649999999  0.5000000003333334 1
>   0.4998976720000000  0.6842284789999999  0.3333333333333333 1
>   0.4523269660000000  0.6779591840000000  0.3333333333333333 1
>   0.4293888700000000  0.6701918600000000  0.5000000000000000 1
>   0.3878383430000000  0.6461980570000000  0.5000000000000000 1
>   0.3696476100000000  0.6302197730000000  0.3333333333333333 1
>   0.3404881770000000  0.5921194460000000  0.3333333333333333 1
>   0.3297786650000000  0.5704059339999999  0.5000000000000000 1
>   0.3173527350000000  0.5240635570000000  0.5000000000000000 1
>   0.3157715210000000  0.4998976720000000  0.3333333333333333 1
>   0.3220408160000000  0.4523269660000000  0.3333333333333333 1
>   0.3298081400000000  0.4293888700000000  0.5000000000000000 1
>   0.3538019430000000  0.3878383430000000  0.5000000000000000 1
>   0.3697802270000000  0.3696476110000000  0.3333333333333333 1
>   0.4078805540000000  0.3404881770000000  0.3333333333333333 1
>   0.4295940660000000  0.3297786650000000  0.4999999996666666 1
>   0.4759364430000000  0.3173527350000000  0.5000000003333334 1
>   0.5001023280000000  0.3157715210000000  0.3333333333333333 1
>   0.5476730340000000  0.3220408160000000  0.3333333333333333 1
>   0.5706111300000000  0.3298081390000000  0.5000000003333334 1
>   0.6121616570000000  0.3538019430000000  0.5000000000000000 1
>   0.6303523900000000  0.3697802270000000  0.3333333333333333 1
>   0.6595118230000000  0.4078805540000000  0.3333333333333333 1
>   0.6702213350000000  0.4295940660000000  0.5000000000000000 1
>   0.6826472649999999  0.4759364430000000  0.5000000000000000 1
>   0.6842284789999999  0.5001023280000000  0.6666666666666666 1
>   0.6779591830000000  0.5476730340000000  0.6666666666666666 1
>   0.6701918610000001  0.5706111300000000  0.8333333333333334 1
>   0.6461980570000000  0.6121616570000000  0.8333333333333334 1
>   0.6302197730000000  0.6303523890000000  0.6666666666666666 1
>   0.5921194460000000  0.6595118230000000  0.6666666666666666 1
>   0.5704059339999999  0.6702213350000000  0.8333333333333334 1
>   0.5240635570000000  0.6826472649999999  0.8333333336666667 1
>   0.4998976720000000  0.6842284789999999  0.6666666666666666 1
>   0.4523269660000000  0.6779591840000000  0.6666666666666666 1
>   0.4293888700000000  0.6701918600000000  0.8333333333333334 1
>   0.3878383430000000  0.6461980570000000  0.8333333333333334 1
>   0.3696476100000000  0.6302197730000000  0.6666666666666666 1
>   0.3404881770000000  0.5921194460000000  0.6666666666666666 1
>   0.3297786650000000  0.5704059339999999  0.8333333333333334 1
>   0.3173527350000000  0.5240635570000000  0.8333333333333334 1
>   0.3157715210000000  0.4998976720000000  0.6666666666666666 1
>   0.3220408160000000  0.4523269660000000  0.6666666666666666 1
>   0.3298081400000000  0.4293888700000000  0.8333333333333334 1
>   0.3538019430000000  0.3878383430000000  0.8333333333333334 1
>   0.3697802270000000  0.3696476110000000  0.6666666666666666 1
>   0.4078805540000000  0.3404881770000000  0.6666666666666666 1
>   0.4295940660000000  0.3297786650000000  0.8333333330000000 1
>   0.4759364430000000  0.3173527350000000  0.8333333336666667 1
>   0.5001023280000000  0.3157715210000000  0.6666666666666666 1
>   0.5476730340000000  0.3220408160000000  0.6666666666666666 1
>   0.5706111300000000  0.3298081390000000  0.8333333336666667 1
>   0.6121616570000000  0.3538019430000000  0.8333333333333334 1
>   0.6303523900000000  0.3697802270000000  0.6666666666666666 1
>   0.6595118230000000  0.4078805540000000  0.6666666666666666 1
>   0.6702213350000000  0.4295940660000000  0.8333333333333334 1
>   0.6826472649999999  0.4759364430000000  0.8333333333333334 1
> %endblock AtomicCoordinatesAndAtomicSpecies
>
> # K-sampling (alternative specification using kgrid_cutoff)
> %block kgrid_Monkhorst_Pack
>  1   0   0   0.0
>  0   1   0   0.0
>  0   0   70  0.0
> %endblock kgrid_Monkhorst_Pack
>
> # Basis set definition
> PAO.BasisSize   DZP
> PAO.EnergyShift 50 meV
> PAO.SplitNorm   0.15
>
> # Real space grid
> MeshCutoff 200.0 Ry
>
> #Convergence of SCF
> MaxSCFIterations 100
> DM.MixingWeight  0.05
> DM.NumberPulay   10
> DM.Tolerance     0.0001
> DM.UseSaveDM     .true.
>
> # Eigenvalue problem: order-N or diagonalization
> SolutionMethod          transiesta
> ElectronicTemperature   5.0 K
>
> TS.WriteHS  .true.
> TS.NumUsedAtomsLeft  32
> TS.NumUsedAtomsRight 32
> TS.HSFileLeft   'cnt.TSHS'
> TS.HSFileRight  'cnt.TSHS'
> TS.TBT.HSFile   'cnt-system.TSHS'
> TS.TBT.Emin    -4.0 eV
> TS.TBT.Emax     4.0 eV
> TS.TBT.NPoints   200
>
> # Density functional (Notice that Xc.authors and XC.functional)
> XC.functional           VDW
> XC.authors              KBM
>
> # Molecular Dynamics and relaxations
> MD.TypeOfRun            CG
> MD.NumCGsteps           0
> MD.VariableCell         .false.
> MD.ConstantVolume       .true.
>
> # Output options
> WriteCoorInitial        .false.
> WriteCoorStep           .true.
> WriteForces             .false.
> WriteKpoints            .false.
> WriteEigenvalues        .false.
> WriteDM                 .true.
> WriteKbands             .false.
> WriteBands              .false.
> WriteWaveFunctions      .true.
> WriteMullikenPop        0
> WriteCoorXmol           .true.
> WriteCoorCerius         .true.
> WriteMDXmol             .true.
> WriteMDhistory          .true.
>
>

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