PDOS calculation with Spin-orbit Coupling |
- Date: 2022/04/01 01:09
- Name: Michele Amato
- Dear all,
I recently started to use Openmx to study the electronic properties of doped Bi2Se3 nanostructures. I am currently focusing on the Projected Density of States (PDOS) calculations for such systems and I have some doubts concerning how PDOS is evaluated when the spin-orbit coupling is taken into account.
When you do not include spin polarization after you select the atoms for evaluating the PDOS, the code prints an output file for each atomic orbital of each selected atom. As specified in the manual, in these files, the first and second columns are energy in eV and PDOS (eV^-1) while the third column is the integrated PDOS.
If the calculation is spin-polarized, the second and third columns in the output files correspond to PDOS for up and down spin states, respectively, and the fourth and fifth columns are the corresponding integrated values.
When I perform the calculation including spin-orbit coupling (by setting scf.SpinPolarization NC and scf.SpinOrbit.Coupling on), the PDOS output file still contains five columns: the first is the energy, the second and third columns ‘remember’ a PDOS for up and down spin states while (I suppose) that the last two columns are the integrated PDOS values. I cannot figure out which is the physical meaning of the second and third columns in this case. Since we know that in the non-collinear calculation the orientation of magnetization can vary in space and there is no particular direction in which all the spins are parallel or anti-parallel, it is not clear to me:
1) how the second and third columns are calculated. I thought that maybe they could be related to the spin moment projection with respect to an arbitrary axis, but I have not found any confirmation of that.
2) Do these two columns contain only information about the spin moment projection or do they include also information about the non-collinear orbital moment?
Any answer or references suggestion about these doubts would be greatly appreciated.
Thank you so much in advance for your reply!