the sequence of doing +U and spin-orbit coupling

[corbin]

Dear all,

I find the sequence of doing +U and spin-orbit coupling will affect the final ground state. For example, if you first do +U calculation and then spin-orbit coupling, the result is different to that of first doing spin-orbit coupling and then +u calculation. How to understand this difference and which is the result to be trusted, the former or the latter?

any comments will be appreciated.

Best,

Bin Shao

[admin]

Final ground state should be independent on the order (LDA+U / SOC or SOC / LDA + U).
If results are different then numerical SCF procedure finds different minima.