Hi everybody,
It is the first time I use SIESTA for my structure that is a molecular wire
(a molecule sandwiched between two gold leads). I want to compare my
results to dftb.
I've already done different examples at package directory. My question is
that why the calculated Fermi level is differ at my calculations:
dftb: Ef=-5.15 eV (seems to be correct)
SIESTA: Ef=3.08 eV (seems lower than real)
And I am not sure about LatticeConstant. It is 4.08 Ang for gold and I
don't know if I can use it for my structure or not (I left it as comment at
my current calculation).
My input:
SystemName C-linker
SystemLabel Clinker
NumberOfAtoms 202
NumberOfSpecies 3
%block ChemicalSpeciesLabel
1 6 C # Species index, atomic number, species label
2 1 H
3 79 Au
%endblock ChemicalSpeciesLabel
#LatticeConstant 4.08 Ang
%block LatticeVectors
17.309974003446687 0.000000000000000 0.000000000000000
0.000000000000000 14.990877225833049 0.000000000000000
0.000000000000000 0.000000000000000 47.814712786
%endblock LatticeVectors
%block kgrid_Monkhorst_Pack
1 0 0 0.0
0 1 0 0.0
0 0 1 0.0
%endblock kgrid_Monkhorst_Pack
xc.functional GGA # Exchange-correlation functional
xc.authors PBE # Exchange-correlation version
MeshCutoff 400. Ry # Mesh cutoff. real space mesh
# SCF options
MaxSCFIterations 400 # Maximum number of SCF iter
DM.MixingWeight 0.010 # New DM amount for next SCF cycle
DM.Tolerance 5.d-3 # Tolerance in maximum difference
DM.UseSaveDM true # to use continuation files
DM.NumberPulay 10
DM.NumberKick 40
DM.KickMixingWeight 0.15
SolutionMethod diagon # OrderN or Diagon
ElectronicTemperature 25 meV # Temp. for Fermi smearing
# MD options
MD.TypeOfRun cg # Type of dynamics:
MD.NumCGsteps 0 # Number of CG steps for
# coordinate optimization
#MD.MaxCGDispl 0.1 Ang # Maximum atomic displacement
# in one CG step (Bohr)
#MD.MaxForceTol 0.001 eV/Ang # Tolerance in the maximum
# atomic force (Ry/Bohr)
AtomicCoordinatesFormat Ang
AtomicCoordinatesFormat Ang
%block AtomicCoordinatesAndAtomicSpecies
...
%endblock AtomicCoordinatesAndAtomicSpecies
#SpinPolarized .true.
#DM.InitSpinAF .true.
# Pour le trace des DOS
%block ProjectedDensityOfStates
-20.00 10.00 0.200 600 eV
%endblock ProjectedDensityOfStates
# Output options
# MD.UseStructFile .true.
WriteKpoints T
WriteCoorStep T
WriteEigenvalues T
MD.UseSaveXV T
WriteCoorXmol T
WriteMullikenPop 1
WriteForces T
I will be really gratful for your kind helping and suggestions.
Best regards,
Raha
--
Visiting researcher at Institute of Physical Chemistry,
Karlsruhe Institute of Technology, Germany.
email:[email protected]
