[Wannier] Comparison projected DOS between projwfc.x and postw90.x

[Dongzhe Li]

Dear Wannier90 developers and users,

I am new Wannier90 user, and I would like to transform the bloch wavefunctions from PWSCF to Wannier basis for molecular junctions (one benzene molecule bridged by metallic leads). I followed the manual, the disentanglement and localization process have been done successfully. The total DOS calculated by PWSCF and by postw90.x are identical, and the Hamiltonian matrix H_{nm}(R) is completely real.

As a initial projection, for benzene molecule, I selected pz orbital for C, and s orbital for H. In addition, for the metallic lead the s and d orbitals are used. However, if I plot projected DOS on molecule with PWSCF (projwfc.x) and projected DOS with postw90.x for 12 MLWFs (6 pz and 6 s orbitals), they are slightly different, for example, a shift of molecular levels like ~0.1 eV. Not like the total DOS, they superpose.

Since I am interested in the transport properties on the molecular junctions, so the molecular levels alignment are very important. I would like to ask, in this case, my Wannierzation is trust-able or not?

Any comments will be appreciated.
Best regards,
Dongzhe

Department of Physics
Univ. Konstanz, Germany