[Wien] Differences in band character plotting using two methods under rotated local basis

[Yichen Zhang]

Dear Lukas,

Thank you very much for your comments and explanations.

1) This could make more sense, as lapw2 -band -qtl averages out equivalent atoms. For all the atoms considered here, they have multiplicity = 2, so they are averaged with another atom in a different layer (related by some symmetry). x -qtl only picks the nonequivalent atoms in case.struct. Therefore, it gives me the local orbital projections I wanted to see. I will have to check the exact symmetry operations that connect the equivalent atoms to understand how lapw2 -qtl differs from x -qtl. Maybe this is the reason, but I don’t immediately see in the crystal structure why px and py would be mixed in lapw2 when averaging, as they seem to have the same local orientation of 45 deg rotated xy, and I assume the same loc rot matrix in case.struct is applied to all equivalent atoms? I don’t know if the loc rot matrix is also rotated by the symmetry operation between equivalent atoms while propagating, which could lead to averaging between px and py.

2) Yes, I use Igor Pro to look at case.qtl, rather than x spaghetti.

3) Yes, it indeed complained about not having case.in1c. I forgot to include that bug in the report. I just copied case.in1 to case.in1c.

4) Yes, I now have read the threads where you and Peter, Gerhard, Laurence discussed about disconnecting or swapping equivalent atoms for hidden spin polarization. In my case, I wanted to look at orbital projections (locally), which has similarities to your discussion.

5) Yes, matrix element rules in ARPES is sometimes not directly indicating orbitals due to multiple scattering. I have checked with KKR one-step calculation with light from different directions to simulate what was seen in experiments. The inferred orbital texture from one-step is qualitatively consistent with the x -qtl results from wien2k. (As you probably know, fully relativistic one-step calculation code does not conveniently project orbital projections to non-relativistic basis, so I resort to wien2k for explicit orbital projections and cross-checking). In the one-step calculations, TR-LEED final state and proper termination plane were used.

Best regards
Yichen