[Wien] LDA+U

[liuzw03 at st.lzu.edu.cn]

Dear Stefaan,
Thank you very much for your helpful explaination.
But I have another question, that is for which system should I use LDA+U and for
which use GGA+U? Prof. Schwarz ever told me that if there is no Oxygen in system
we need not use LDA+U. My studying system is monoatomic iron wires, so I need not
use LDA+U?


Thank you again!


Zaiwen Liu
>
> You are mixing two things. In order to calculate an orbital moment, you
> should use either LDA, GGA, LDA+U or GGA+U (all with spin-orbit
> coupling) and run after the scf-cycle the lapwdm program with suitable
> input in case.indmc (see the usersguide). (for LDA+U and GGA+U the
> orbital moment is written to case.scf as well, but the same quantity you
> will be able to obtain from lapwdm) Hence, for calculating orbital
> moments you do NOT need the -orb switch, or 'x orb'. The meaning of this
> switch is turning on LDA+U (or GGA+U).
> 
> Stefaan
>