[Wien] Magnetocrystalline anisotropy

[Laurence Marks]

Dear Xavier,

The method you just used avoids time-reversal symmetry for -orb. My
intuition is that this is right, but I don't think I ever convinced
Peter of this. An alternative (that might be wrong) and avoids double
counting is:

Setup case.inso with NO spin-orbit on any atom, then do
runsp_lapw -eece -p -ec 0.00001 -NI -so

Then for larger EMAX and kmesh, edit case.inso and  witht SO do :

x lapw1 -up -c
x lapw1 -dn -c

And for the different magnetization directions we do:

x lapwso -c -up -orb
x lapw2 -so -up  -c
x lapw2 -so -dn  -c

---
Concerning the two question William asked:

1) -eece does not have vorbdu as nobody (to my knowledge) has worked
out what it should be. For certain I don't know!

2) I am not sure about this. Is the imaginary component neglected for
lapw1 -c? For a d-state (as you have) maybe from time-reversal vorb
has to be centro-symmetric so there should be no imaginary term. This
does not seem right for p or f states. Unfortunately it is more than a
year since I worried about this, so I cannot remember.

On Tue, Jan 16, 2018 at 11:02 AM, Xavier Rocquefelte
<xavier.rocquefelte at univ-rennes1.fr> wrote:
> Dear Peter and Laurence
>
> Thank you for your replies. Using the following strategy it seems to work
> nicely (preliminary results):
>
> runsp_lapw -eece -p -ec 0.00001 -NI
>
> Then for larger EMAX and kmesh without SO we do :
>
> x lapw1 -up -c -orb
> x lapw1 -dn -c -orb
>
> And for the different magnetization directions we do:
>
> x lapwso -c -up
> x lapw2 -so -up  -c
> x lapw2 -so -dn  -c
>
>
> In other words, we do not put -orb in lapwso. It seems that this option was
> leading to problems depending on the magnetic system.
>
> Best Regards
> Xavier
>
>
> Le 16/01/2018 à 17:57, William Lafargue-dit-Hauret a écrit :
>
> Dear Profs. Blaha and Marks,
>
> Thank you for your advices. I have a question regarding your comment on the
> EECE case.
>
> The resulting effective potential of LDA+U and EECE corrections is
> decomposed in vorb files, but I don't understand why the spin-coupling file
> case.vorbud shouldn't appear in the second case.
>
> I have a second question regarding the reading of these orbital potential
> files. We noticed the orb program read only the real part, neglecting the
> imaginary one (Prof. Marks already noticed it in the source code). Due to
> our energy scale which is tiny, could we expect an impact of such
> approximation ? Considering your last comments, it seems not due to the
> execution of the orb program only in lapw1 and not during the perturbative
> procedure.
>
> Thank you by advance.
>
> All the best,
>
> William Lafargue-dit-Hauret
>

-- 
Professor Laurence Marks
"Research is to see what everybody else has seen, and to think what
nobody else has thought", Albert Szent-Gyorgi
www.numis.northwestern.edu ; Corrosion in 4D: MURI4D.numis.northwestern.edu
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