Dear all,
I am new in siesta and would like to perform molecular dynamics calculation
on graphene sheet with periodic boundary conditions and the total number of
C atoms 200.
I set the temperature to 300K, but in the output the temperature
fluctuations are very large between 230 to 360 K.
I copy the input file here.
Would any one help me what is wrong in my calculations?
# fdf file
SystemName graphene
SystemLabel c
NumberOfAtoms 200
NumberOfSpecies 1
%block ChemicalSpeciesLabel
1 6 C
%endblock ChemicalSpeciesLabel
XC.functional GGA
XC.authors PBE
LatticeConstant 2.471763457 Ang
%block LatticeParameters
10 8.66025404 8 90. 90. 90.
%endblock LatticeParameters
AtomicCoordinatesFormat Ang
AtomicCoordinatesAndAtomicSpecies < xyz
%block kgrid_Monkhorst_Pack
1 0 0 0.0
0 1 0 0.0
0 0 1 0.0
%endblock kgrid_Monkhorst_Pack
MeshCutoff 300.0 Ry
# SCF options
MaxSCFIterations 100 # Maximum number of SCF iter
DM.NumberPulay 3 # One Pulay every 3 iter
DM.MixingWeight 0.25 # New DM amount for next SCF cycle
DM.Tolerance 5.d-4 # Tolerance in maximum difference
SolutionMethod diagon # OrderN or Diagon
ElectronicTemperature 25 meV # Temp. for Fermi smearing
# structural infomation
AtomCoorFormatOut Ang
WriteCoorXmol T
WriteMDXmol T
WriteForces T
# options for MD
MD.MaxForceTol 0.01 eV/Ang
MD.TypeOfRun Nose
MD.VariableCell T
MD.NumCGSteps 400
MD.Broyden.History.Steps 6
MD.Broyden.Initial.Inverse.Jacobian 1.0
MD.InitialTimeStep 1
MD.FinalTimeStep 2000
MD.LengthTimeStep 1 fs
MD.InitialTemperature 300 K
MD.TargetTemperature 300 K
MD.AnnealOption TemperatureAndPressure
MD.TauRelax 100.0 fs
