[Pw_forum] d-orbitals in fully relativistic pseudopotential for Carbon -- band gap in graphene

[Martin Gmitra]

Dear all,
Could you provide an advice how I can generate fully relativistic
pseudopotential for Carbon which
would include effect of unoccupied d-orbitals?

We have learned [Phys. Rev. B 80, 235431 (2009)] using fully potential
linearized augmented
plane wave techniques (FPLAPW: Wien2k, FLEUR) that spin-orbit coupling
leads to band gap
opening in graphene at K-point of about 24 micro eV. If d-orbitals are
not taken into account
the band gap shrinks below 1 micro eV. The band gap I have obtained by
using QE v5.0 and
generating a fully relativistic pseudopotential with ld1.x for Carbon
atom is 0.96 micro eV, which
agrees well with FPLAPW techniques when d-orbitals are not considered.

Is it possible to generate fully relativistic pseudopotential for
Carbon atom which would include
effects of d-orbitals for spin-orbit coupling induced band gap in graphene?

Best regards,
Martin Gmitra