[Wien] Choice of magnetization axis in the case with spin-orbit coupling

[Rocquefelte]

You must try different directions in order to find the magnetization 
easy axis.
Such a direction is perhaps experimentally know in your case. Thus you 
can check by considering few crystallographic directions.

Should I always use positive values for (h k l)?
Or should I choose (0 0 1) when I prepare the spin moment to be up, that
is, during the stage of "instgen_lapw -ask"


The answer is no. The spin sign (up/down) has no relationship with the 
direction of the magnetic moment.
You are just imposing a given direction in real-space for the magnetic 
moments when you specify the (h k l) direction.

Cheers

Xavier



Le 29/07/2014 16:04, Zhu, Jianxin a écrit :
> Dear Peter and Wien2k users,
>
> For the spin-orbit case, when we run initso_lapw, we are prompted to
> choose the moment direction
>
> ---->Please select the direction of the moment ( h k l )
>
> I notice that the choices of e.g.,  (0  0  1) and (0  0  -1) give slight
> different values.
> In particular, when I choose (0  0  1), I obtain from LDA+U+SO
>
> :MMINT: MAGNETIC MOMENT IN INTERSTITIAL =   -0.32640
> :MMI001: MAGNETIC MOMENT IN SPHERE   1    =   -4.71648
>
> :ORB001:  ORBITAL MOMENT:  0.00000  0.00000  4.59939 PROJECTION ON M
> 4.59939
>
> while with (0 0 -1), I obtain from LDA+U+SO with the rest of conditions
> the same
>
> :MMINT: MAGNETIC MOMENT IN INTERSTITIAL =   -0.34861
> :MMI001: MAGNETIC MOMENT IN SPHERE   1    =   -4.72342
>
>
> :ORB001:  ORBITAL MOMENT:  0.00000  0.00000  4.52838 PROJECTION ON M
> -4.52838
>
>
> Should I always use positive values for (h k l)?
> Or should I choose (0 0 1) when I prepare the spin moment to be up, that
> is, during the stage of "instgen_lapw -ask"
> select spinpolarization up, dn or non-magnetic ( u, d, n )
> u
>
> while (0 0 -1) when I prepare the spin moment to be down, that is, during
> the stage of "instgen_lapw -ask"
> select spinpolarization up, dn or non-magnetic ( u, d, n )
> d
>
>
> I appreciate if you can share your thought.
>
>
>
> Thanks,
>
> Jianxin
>
> _______________________________________________
> Wien mailing list
> Wien at zeus.theochem.tuwien.ac.at
> http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien
> SEARCH the MAILING-LIST at:  http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html