[Wien] Problems with FM+U+SOC

 

pluto Fri, 24 Jul 2020 09:04:23 -0700

Dear All,

I am trying to calculate a simple 4f compound with GGA+U, ferromagnetic exchange (FM) and SOC. FM calculation without SOC using the literature U settings looks reasonable, I am getting a gapped band structure similar to anyone else. But running SCF with GGA+U and SOC removes the gap, it also seems to change the exchange splitting of 4f, which basically tells me that U on 4f is not in effect anymore. Actually the problem happens with this inorb file, when natorb=1 and nlorb=2:

  1  1  0                     nmod, natorb, ipr
PRATT  1.0                    BROYD/PRATT, mixing
  1 2 2 3                          iatom nlorb, lorb
  1                              nsic 0..AMF, 1..SIC, 2..HFM
   0.25 0.00        U J           U on d levels
   0.42 0.00        U J           U on f levels

When nlorb is reduced to 1, and U is used only for 4f levels things start to look "normal" also with SOC. So, it seems SOC cannot handle nlorb>1 (perhaps just a bug). I am using couple of years old version of WIEN2k, perhaps this has been fixed in the meantime. Otherwise, any comment would be appreciated!

Best,
Lukasz

https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg20322.html