Magmom units in exchange.out file

[Leo Tan]

Dear Dr. He and co.,

Thank you for your work on TB2J! I'm currently working with Dr. Bo Peng on magnetism, and am running calculations with VASP and Wannier90 before using TB2J. 

My understanding for VASP magnetic moment (in INCAR and OUTCAR) is that it is interpreted in either Bohr magnetons or 1 electrons' worth of magnetic moment. After running wann2J.py in TB2J, a set of local magnetic moments are printed - I was wondering which bits of information from VASP/W90 runs are used to determine the magmom, and if I may also interpret the units of magmom the same way as in VASP? 

Additionally, am I right to say that I should be expecting the local magnetisation in exchange.out to be reasonably close to that in VASP OUTCAR? (That is my understanding from reading this page https://tb2j.readthedocs.io/en/latest/src/output.html)

Thank you!

Yours sincerely,

Leo Tan

[Xu He]

Hello, 

When using TB2J with VASP-Wannier90, the magnetic moment is from the Wannier functions. It computes the density matrix from the Wannier function Hamiltonian and then computes the magnetic moments, so no reading of the magmom from VASP output is done. 

The unit is the same (Bohr magneton). Indeed the magnetic moments should be close to the DFT result. But it doesn't have to be exactly the same. In VASP, the magmom is integrated inside the paw sphere by default. And in TB2J, it uses the projection to the Wannier functions. 

If the numbers are too different, indeed it hints there are problems (often in the Wannierization procedure).

 Best, 

HeXu

--
You received this message because you are subscribed to the Google Groups "TB2J" group.
To unsubscribe from this group and stop receiving emails from it, send an email to tb2j+uns...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/tb2j/6c1d1287-a6c5-4525-a6df-627a61287db2n%40googlegroups.com.
For more options, visit https://groups.google.com/d/optout.