[DFTB-Plus-User] Molecular dynamics

[Mogus Mochena]

Dear All:
  I am a new user of DFTB+. I have tried to calculate finite-temperature
structures using Molecular dynamics with NVT. I ran the input below for
Icosahedral Fe13 cluster for three different temperatures: 1500K, 2000 K,
2500 K. The structures I got were not different from the ground-state
structure; so I am not sure whether my input is correct or not.

Anteneh Tefera
Graduate Student
Florida A & M University






Geometry = GenFormat {
 <<< "INPUT_Fe13.gen"
}
Driver = VelocityVerlet {
  MovedAtoms = Range { 1 -1 }
  Steps = 1000000
  TimeStep = 400.0e-15                #Time interval between two MD steps
  KeepStationary = No               #Remove translational motion from the
system
  MDRestartFrequency=10
  Thermostat = NoseHoover{
  Temperature[Kelvin] = 2500
#  ReselectProbability = 0.5
#ReselectIndividually = Yes
#AdaptFillingTemp = Yes
  CouplingStrength=100
  }
  OutputPrefix = "MDFe13geom.out"
}

Hamiltonian = DFTB {
  SCC = Yes
  SCCTolerance = 1.0e-5
  MaxSCCIterations = 1000
  Mixer = Broyden {
    MixingParameter = 0.2
  }

SlaterKosterFiles = {
    Fe-Fe = "Fe-Fe.skf"
}
  MaxAngularMomentum = {
    Fe = "d"
  }
  Charge = 0.0
  SpinPolarisation = {}       #spin polarisation contributions to the energy
or band-structure.
  Filling = Fermi {
    Temperature [Kelvin] = 300.0
  }
}
#ReadInitialCharge = No
Options = {}

ParserOptions = {
  ParserVersion = 3
}