scf is not converging in transiesta calculation

Asked by nayana devaraj on 2018-05-05

Hi,
 In the transiesta calculation of scattering region, scf is not converging in maximum number of steps.
Following is my fdf file.

NumberOfSpecies 3
%block ChemicalSpeciesLabel
 1 27 Co
   2 42 Mo
   3 16 S
%endblock ChemicalSpeciesLabel
PAO.BasisSize DZP
PAO.EnergyShift 50 MeV
PAO.SplitNorm 0.15392
==================================================
==================================================
# K-points
%block kgrid_Monkhorst_Pack1
1 0 0 0.0
0 1 0 0.0
0 0 1 0.0
%endblock kgrid_Monkhorst_Pack
==================================================
==================================================
# UNIT CELL
LatticeConstant 1.00 Ang
%block LatticeVectors
        6.4800944328 0.0000000000 0.0000000000
        3.2397546226 5.6116284136 0.0000000000
        0.0671003143 0.1085815314 21.0425682725

%endblock LatticeVectors
# Atomic coordinates
NumberOfAtoms 68
AtomicCoordinatesFormat Ang
%block AtomicCoordinatesAndAtomicSpecies
     5.112454135 3.515927420 0.848693033 1
     1.409485878 0.307116574 0.846854638 1
     2.803578198 4.315530649 0.846902378 1
     6.967535515 5.115720693 0.848833272 1
     5.575636034 1.106961286 0.850097306 1
     3.259137901 1.909268718 0.851260373 1
     7.429142444 2.710101022 0.852619493 1
     2.798608710 0.566608299 2.823432118 1
     4.652972604 2.175442883 2.823783931 1
     2.333388624 2.980868539 2.824679768 1
     8.349258565 5.379164071 2.828240854 1
     4.186274271 4.577332776 2.829493521 1
     6.968212779 1.371824558 2.830029393 1
     6.500643842 3.775944610 2.831124340 1
     3.259232369 1.902967217 4.785325017 1
     5.582851351 1.093165878 4.817304242 1
     1.399543888 0.293162930 4.817446911 1
     2.794712396 4.314588549 4.816853344 1
     5.103331239 3.505233682 4.821580555 1
     6.969029798 5.117102142 4.822982476 1
     7.430755679 2.693319364 4.824651549 1
     4.665139732 2.139566083 6.757980818 1
     2.763758897 0.563696591 6.758577207 1
     2.350547580 2.996575167 6.765856158 1
     6.498558656 3.772204153 6.791396769 1
     4.170876697 4.550036557 6.812115474 1
     8.340410956 5.393832616 6.822402708 1
     6.986779687 1.364950895 6.824110975 1
     4.905726514 1.066903979 8.710430583 3
     1.712523840 0.930489981 8.711768851 3
     3.196033732 3.782392606 8.717059214 3
     6.509410837 3.787087993 8.895438997 3
     4.862708882 4.711614299 10.343254912 2
     8.128840767 4.776196708 10.346335940 2
     6.524284754 1.898615338 10.349514798 2
     3.276209351 1.927074099 10.377408353 2
     1.655662536 0.937035903 11.879056027 3
     3.227403013 3.831133361 11.898469073 3
     4.921765641 1.014842586 11.925075156 3
     6.524202114 3.780392881 12.075234656 3
     1.481584112 0.462207932 13.951835825 1
     2.901417224 4.395329414 13.956262019 1
     5.610682132 1.191346677 13.960461197 1
     5.208297760 3.633955046 13.973266935 1
     7.032151259 5.206461773 13.979356245 1
     7.473847042 2.837689380 13.997251667 1
     3.330282009 2.024580752 14.018300236 1
     8.427954634 5.477724319 15.938484810 1
     4.268049234 4.707169103 15.937781184 1
     7.015885128 1.487999506 15.940683484 1
     2.878094866 0.696398490 15.949954787 1
     4.713494650 2.292793692 15.950594447 1
     2.410778793 3.078725654 15.953969593 1
     6.567099203 3.898600797 15.957002333 1
     1.479490501 0.423885365 17.935111233 1
     7.494391816 2.824955823 17.935557741 1
     5.181475679 3.626689345 17.936293977 1
     2.867838104 4.427896914 17.936936145 1
     5.644764529 1.220746095 17.937720042 1
     7.033487549 5.228421605 17.938575430 1
     3.333497084 2.022260181 17.944027588 1
     4.259682848 4.692103264 19.911552001 1
     8.420995633 5.495657101 19.915220638 1
     2.404430689 3.090242127 19.915991993 1
     7.035996482 1.487778144 19.916828567 1
     2.869522178 0.684433088 19.917872091 1
     4.720483408 2.288607502 19.918313581 1
     6.571430737 3.889509256 19.923804621 1

%endblock AtomicCoordinatesAndAtomicSpecies
TS.Hartree.Fix elec-box
==================================================
==================================================
# General variables
ElectronicTemperature 300 K # room temperature
MeshCutoff 300. Ry
xc.functional GGA # Exchange-correlation functional
xc.authors PBE
SpinPolarized .false.
SolutionMethod Transiesta
==================================================
==================================================
# SCF variables
DM.MixSCF1 T
MaxSCFIterations 800 # Maximum number of SCF iter
DM.MixingWeight 0.03 # New DM amount for next SCF cycle
DM.Tolerance 1.d-4 # Tolerance in maximum difference
DM.NumberPulay 5
Diag.DivideAndConquer no
MixHamiltonian yes
UseSaveData .true.
DM.UseSaveDM .true. # to use continuation files
MD.UseSaveXV .true.
MD.UseSaveCG T
# MD variables
MD.FinalTimeStep 1
MD.TypeOfRun CG
MD.NumCGsteps 000
MD.UseSaveXV .true.
==================================================
==================================================
# Output variables
WriteMullikenPop 1
WriteBands .true.
SaveRho .true.
SaveDeltaRho .true.
SaveHS .true.
SaveElectrostaticPotential True
SaveTotalPotential no
WriteCoorXmol .true.
WriteMDXmol .true.
WriteMDhistory .false.
WriteEigenvalues yes
Longoutput true
TBT.Projs.DOS.A true
TBT.DOS.A.All true #Calculate the DOS from the spectral function and do so with all electrodes

==================================================
==================================================
# Parallel variables
Diag.ParallelOverK yes
==================================================
==================================================
# Transiesta information
TS.Voltage 0.00000 eV
%block TS.ChemPots
  Left
  Right
%endblock TS.ChemPots
%block TS.ChemPot.Left
  mu V/2
  contour.eq
    begin
      c-Left
      t-Left
    end
%endblock TS.ChemPot.Left
%block TS.ChemPot.Right
  mu -V/2
  contour.eq
    begin
      c-Right
      t-Right
    end
%endblock TS.ChemPot.Right
TS.Elecs.Bulk true
TS.Elecs.DM.Update none
TS.Elecs.Neglect.Principal true
TS.Elecs.GF.ReUse true
%block TS.Elecs
  Left
  Right
%endblock TS.Elecs
%block TS.Elec.Left
  TSHS ./Co_elec_left.TSHS
  chem-pot Left
  semi-inf-dir -a3
  elec-pos begin 1
%endblock TS.Elec.Left
%block TS.Elec.Right
  TSHS ./Co_elec_right.TSHS
  chem-pot Right
  semi-inf-dir +a3
  elec-pos end -1
%endblock TS.Elec.Right
TS.Contours.Eq.Pole 2.50000 eV
%block TS.Contour.c-Left
  part circle
   from -40.00000 eV + V/2 to -10. kT + V/2
    points 30
     method g-legendre
%endblock TS.Contour.c-Left
%block TS.Contour.t-Left
  part tail
   from prev to inf
    points 10
     method g-fermi
%endblock TS.Contour.t-Left
%block TS.Contour.c-Right
  part circle
   from -40.00000 eV - V/2 to -10. kT - V/2
    points 30
     method g-legendre
%endblock TS.Contour.c-Right
%block TS.Contour.t-Right
  part tail
   from prev to inf
    points 10
     method g-fermi
%endblock TS.Contour.t-Right
TS.Elecs.Eta 0.0001 eV
%block TS.Contours.nEq
  neq
%endblock TS.Contours.nEq
%block TS.Contour.nEq.neq
  part line
   from -|V|/2 - 5 kT to |V|/2 + 5 kT
    delta 0.01 eV
     method mid-rule
%endblock TS.Contour.nEq.neq
# TBtrans options
TBT.Elecs.Eta 0.0001 eV
%block TBT.Contours
  neq
%endblock TBT.Contours
%block TBT.Contour.neq
  part line
   from -1.0000 eV to 1.0000 eV
    delta 0.01000 eV
     method mid-rule
%endblock TBT.Contour.neq
TBT.T.Eig 3

Question information

Language:
English Edit question
Status:
Answered
For:
Siesta Edit question
Assignee:
No assignee Edit question
Last query:
2018-05-05
Last reply:
2018-05-06
Nick Papior (nickpapior) said : #1

There are no general solutions for the problem of convergence problems. You have to try-by-error.

Can you help with this problem?

Provide an answer of your own, or ask nayana devaraj for more information if necessary.

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