[DFTB-Plus-User] graphene energy band calculations

[Alexander Dobrinsky]

Dear dftb users. I was wondering what are the best parameters to use
for graphene energy band calculations. I have tried mio and pbc
Slater-Koster sets. Unfortunately my conduction energy bands turn out
to be incorrect and do not match results available  in the literature
(ref: Physical Properties of Carbon Nanotubes, Dresselhaus). Here I am
pasting in my dftb+ input file:

Geometry = {
  Periodic = Yes
  LatticeVectors [Angstrom] = {
    2.46  0.00  0.00
    1.23  2.13042249  0.00
    0.00  0.0   12.0
  }
 TypeNames = { "C" }
 TypesAndCoordinates [Angstrom] = {
   1  0.00  0.00  0.00
   1 1.230000000 -0.710130000  0.0000000000000
 }
}

Hamiltonian = DFTB {
  SCC = Yes
  SCCTolerance = 1e-5
  MaxSCCIterations = 1
  MaxAngularMomentum = {
    C = "p";
  }
  SlaterKosterFiles = Type2FileNames {
    Prefix = "../../pbc-0-2/"
    Separator = "-"
    Suffix = ".skf"
  }

  KPointsAndWeights = KLines {
    1   0.666666666  0.333333333333  0.0   # K just calculate a single K point
    20  0.0  0.0  0.0   # Gamma (000)
    20  0.5  0.5  0.0   # M (100)
    20  0.666666666 0.333333333333  0.0 # K point
  }
  ReadInitialCharges = Yes
}
Options = {
  RestartFrequency = 0
}

Thank you very much for your help!
Alex