Well, all of those calculations have errors ;) 1) Too short electrode, too short device 2) Electrode (seems!) ok, too short device 3) too short electrode, device (seems!) ok.
The device *must* also be so big that no direct interaction between left-right takes place. You can check how the interaction table is by looking at the BONDS file. There has been several questions about this previously so search the mailing list. Lastly, you may want to try the trunk version which prints out if your electrode is too small. 2015-10-30 10:31 GMT+01:00 Damien Tristant <[email protected]>: > Thank Nick Papior for your help, but unfortunately I got the same problem. > Enclosed, I put the Transmission spectra and a picture of 3 different > systems : > - 96 atoms (1 unit cell for left electrode ; 1 unit cell for the sample ; > 1 unit cell for the right electrode) > - 160 atoms (2 unit cells for left electrode ; 1 unit cell for the sample > ; 2 unit cells for the right electrode) > - 128 atoms (1 unit cell for left electrode ; 2 unit cells for the sample > ; 1 unit cell for the right electrode) > As you can see the problem remains the same. > May be the problem comes from the calcul of the complex contour? > Best regards. > > Damien > > > > On 30/10/2015 07:23, Nick Papior wrote: > > 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. >> >> > -- Kind regards Nick
