Dear all,

I am a phd student and I am new to siesta , I am doing a Transiesta
calculation for a system that consist of two graphene sheets sandwiching
three cobalt atoms, as the electrode calculation is successfully done, the
SCF iterations in SR calculation are not converging where my input file is

SystemName          SR.Co
SystemLabel         SR.Co

NumberOfAtoms       131
NumberOfSpecies        2

%block ChemicalSpeciesLabel
  1   6  C
  2   27 Co
%endblock ChemicalSpeciesLabel

PAO.BasisSize  SZP
PAO.EnergyShift  0.05 Ry
PAO.SplitNorm    0.2

==================================================
==================================================
# K-points

%block kgrid_Monkhorst_Pack
   1   0   0  0.0
   0   1   0  0.0
   0   0   1  0.5
%endblock Kgrid_Monkhorst_Pack
==================================================
==================================================
# UNIT CELL AND ATOMIC POSITIONS

# UNIT CELL
LatticeConstant     1.00 Ang

%block LatticeVectors
17.016 0.000 0.000
0.000 9.824 0.000
0.000 0.0000 14.000
%endblock LatticeVectors
AtomicCoordinatesFormat Ang

%block AtomicCoordinatesAndAtomicSpecies

0.000 0.000 0.000 1
1.418 0.000 0.000 1
2.127 1.228 0.000 1
3.545 1.228 0.000 1
4.254 0.000 0.000 1
5.672 0.000 0.000 1
6.381  1.228 0.000 1
7.799  1.228 0.000 1
8.508  0.000 0.000 1
9.926  0.000 0.000 1
10.635 1.228 0.000 1
12.053 1.228 0.000 1
12.762 0.000 0.000 1
14.180 0.000 0.000 1
14.889 1.228 0.000 1
16.304 1.228 0.000 1
0.000  2.456 0.000 1
1.418  2.456 0.000 1
2.127  3.684 0.000 1
3.545  3.684 0.000 1
4.254  2.456 0.000 1
5.672  2.456 0.000 1
6.381  3.684 0.000 1
7.799  3.684 0.000 1
8.508  2.456 0.000 1
9.926  2.456 0.000 1
10.635 3.684 0.000 1
12.053 3.684 0.000 1
12.762 2.456 0.000 1
14.180 2.456 0.000 1
14.889 3.684 0.000 1
16.307 3.684 0.000 1
0.000  4.912 0.000 1
1.418  4.912 0.000 1
2.127  6.140 0.000 1
3.545  6.140 0.000 1
4.254  4.912 0.000 1
5.672  4.912 0.000 1
6.381  6.140 0.000 1
7.799  6.140 0.000 1
8.508  4.912 0.000 1
9.926  4.912 0.000 1
10.635 6.140 0.000 1
12.053 6.140 0.000 1
12.762 4.912 0.000 1
14.180 4.912 0.000 1
14.889 6.140 0.000 1
16.307 6.140 0.000 1
0.000  7.368 0.000 1
1.418  7.368 0.000 1
2.127  8.596 0.000 1
3.545  8.596 0.000 1
4.254  7.368 0.000 1
5.672  7.368 0.000 1
6.381  8.596 0.000 1
7.799  8.596 0.000 1
8.508  7.368 0.000 1
9.926  7.368 0.000 1
10.635 8.596 0.000 1
12.053 8.596 0.000 1
12.762 7.368 0.000 1
14.180 7.368 0.000 1
14.889 8.596 0.000 1
16.307 8.596 0.000 1
7.0900  4.912 1.400 2
7.0900  4.912 3.900 2
7.0900  4.912 6.400 2
0.000  0.000 7.800 1
1.418  0.000 7.800 1
2.127 1.228 7.800 1
3.545 1.228 7.800 1
4.254 0.000 7.800 1
5.672 0.000 7.800 1
6.381  1.228 7.800 1
7.799  1.228 7.800 1
8.508  0.000 7.800 1
9.926  0.000 7.800 1
10.635 1.228 7.800 1
12.053 1.228 7.800 1
12.762 0.000 7.800 1
14.180 0.000 7.800 1
14.889 1.228 7.800 1
16.304 1.228 7.800 1
0.000  2.456 7.800 1
1.418  2.456 7.800 1
2.127  3.684 7.800 1
3.545  3.684 7.800 1
4.254  2.456 7.800 1
5.672  2.456 7.800 1
6.381  3.684 7.800 1
7.799  3.684 7.800 1
8.508  2.456 7.800 1
9.926  2.456 7.800 1
10.635 3.684 7.800 1
12.053 3.684 7.800 1
12.762 2.456 7.800 1
14.180 2.456 7.800 1
14.889 3.684 7.800 1
16.307 3.684 7.800 1
0.000  4.912 7.800 1
1.418  4.912 7.800 1
2.127  6.140 7.800 1
3.545  6.140 7.800 1
4.254  4.912 7.800 1
5.672  4.912 7.800 1
6.381  6.140 7.800 1
7.799  6.140 7.800 1
8.508  4.912 7.800 1
9.926  4.912 7.800 1
10.635 6.140 7.800 1
12.053 6.140 7.800 1
12.762 4.912 7.800 1
14.180 4.912 7.800 1
14.889 6.140 7.800 1
16.307 6.140 7.800 1
0.000  7.368 7.800 1
1.418  7.368 7.800 1
2.127  8.596 7.800 1
3.545  8.596 7.800 1
4.254  7.368 7.800 1
5.672  7.368 7.800 1
6.381  8.596 7.800 1
7.799  8.596 7.800 1
8.508  7.368 7.800 1
9.926  7.368 7.800 1
10.635 8.596 7.800 1
12.053 8.596 7.800 1
12.762 7.368 7.800 1
14.180 7.368 7.800 1
14.889 8.596 7.800 1
16.307 8.596 7.800 1

%endblock AtomicCoordinatesAndAtomicSpecies

# General variables

ElectronicTemperature  100 K
MeshCutoff           350. Ry
xc.functional         GGA           # Exchange-correlation functional
xc.authors            PBE
SpinPolarized .false.
SolutionMethod Transiesta

==================================================
==================================================
# SCF variables

DM.MixSCF1   T
MaxSCFIterations    4000           # Maximum number of SCF iter
DM.MixingWeight       0.2          # New DM amount for next SCF cycle
DM.Tolerance          0.0009        # Tolerance in maximum difference
DM.UseSaveDM          true          # to use continuation files
DM.NumberPulay         5
Diag.DivideAndConquer  no
Diag.ParallelOverK     yes

==================================================
==================================================
# 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

==================================================
==================================================

# Transiesta information

# GF OPTIONS
TS.ComplexContour.Emin    -30.0 eV
TS.ComplexContour.NPoles       03
TS.ComplexContour.NCircle      30
TS.ComplexContour.NLine        10
TS.RealContour.Emin       -30.0 eV
TS.RealContour.Emax        20.0 eV

# BIAS OPTIONS
TS.biasContour.NumPoints       10
# TS OPTIONS
TS.Voltage 0.000000 eV

# TBT OPTIONS
TS.TBT.Emin -5.0 eV
TS.TBT.Emax +5.0 eV
TS.TBT.NPoints 100
TS.TBT.NEigen 3
TS.TBT.Eta        0.000001 Ry

# Write hamiltonian
TS.SaveHS   .true.

# LEFT ELECTRODE
TS.HSFileLeft  ./elec.arm.TSHS
TS.NumUsedAtomsLeft  64
TS.BufferAtomsLeft    0

# RIGHT ELECTRODE
TS.HSFileRight  ./elec.arm.TSHS
TS.NumUsedAtomsRight  64
TS.BufferAtomsRight    0
UseSaveData true
 can please anyone help me to know how can i reach convergence knowing that
he SCF iterations reached about 300 iteration without showing any sign of
convergence.
Thanks in advance
-- 
SIESTA is supported by the Spanish Research Agency (AEI) and by the European 
H2020 MaX Centre of Excellence (http://www.max-centre.eu/)

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