Example: Phonons

Download GraphenePhonons.run

A phonon calculation should be performed at the equilibrium geometry.

In the first calculation we optimize the geometry, including the lattice vectors. We also set the criteria a bit more strict.

$ADFBIN/band << eor
Title Graphene geometry optimization

Units
  Length Angstrom
end

! For Graphene we need to use a symmetryc grid
KSpace 5 &
   Grid Symmetric
End

ATOMS
  C   0.0 0.0 0.0
  C   1.23 0.7101408312 0.0
END

Lattice
   2.46 0.000000 0
   1.23 2.130422493 0
End

GeoOpt
  OptimizeLattice true
  Converge grad=1e-5
End

BasisDefaults
  BasisType DZ
end

end input
eor

mv RUNKF Graphene.runkf

In the second calculation we use the pre-optimized geometry. (See details of the Restart key block) Then we define a supercell and perform a phonon run by using the RunType and PhononConfig key blocks. Note that KSpace can be chosen a bit lower, since we now have a bigger unit cell.

$ADFBIN/band << eor
Title Graphene phonon calc

Units
  Length Angstrom
end

KSpace 3 &
   Grid Symmetric
End

Restart
  File Graphene.runkf
  Geometry
End

runtype
  phonons
end

phononConfig
  stepSize 0.0913
  superCell
    2 0
    0 2
  subend
end

ATOMS
  C   0.0 0.0 0.0
  C   1.23 0.7101408312 0.0
END

Lattice
   2.46 0.000000 0
   1.23 2.130422493 0
End

BasisDefaults
  BasisType DZ
end

end input
eor