2.4. Symmetrization of wannier90_hr.dat New usesful for ir2tb¶
Here is a brief introduction of the symmetrization functionalities. Basically, wannhr_symm is an independent package based on Python2.7 written by Changming Yue (yuechangming8@gmail.com). Although this package is very useful, its requirement is also very restrict.
- The Wannier functions must be atomic like, which means there should be very weak hybridization between orbitals. It’s not possible to deal with the sp2, sp3 like wannier orbitals.
- At present, it can only take care of the s, p, d, t2g, eg orbitals. p orbitals means all three orbitals ordered with pz, px, py. d orbitals are ordered as “dz2”, “dxz”, “dyz”, “dx2-y2”, “dxy”. Such situation is automatically satisfied with in VASP+Wannier90
- The file name of tight binding Hamiltonian should be ‘wannier90_hr.dat’
- This symmetrization process is crucial to run “ir2tb” to order to obtain the correct irreducible representations, since the Wannier90 usually does not enforce the symmetries of the system.