[Wien] Magnetization axis, SOC, and rotation

[Zhu, Jianxin]

Hi Leandro,

If it is with respect to the lattice vectors, is it with respect to the primitive lattice vectors or conventional lattice vectors, when we have fcc/bcc or bct structures?

I see in other electronic structure codes that the spin axis coordinate system is tied to the laboratory ie. Cartesian coordinate system. I will look back into the definition.

Thanks,

Jianxin

From: Wien <wien-bounces at zeus.theochem.tuwien.ac.at> on behalf of Leandro Salemi <leandro.salemi at physics.uu.se>
Reply-To: A Mailing list for WIEN2k users <wien at zeus.theochem.tuwien.ac.at>
Date: Friday, April 6, 2018 at 5:05 PM
To: A Mailing list for WIEN2k users <wien at zeus.theochem.tuwien.ac.at>
Subject: Re: [Wien] Magnetization axis, SOC, and rotation


Dear Jianxin,



The direction chosen in initso is with respect to the lattice vectors (not to cartesian coordinates).

For a cubic system, it does not really matter but it is not true in general !

For instance, if you have a tetragonal system, the magnetization along 111 does not mean that the cartesian vector is 111.



The cartesian basis xyz is something that we define and there exists an infinite number of ways of defining it. On the contrary, the crystallographic system is fixed once the atomic positions are known. Hence, it would make sense to say that "the magnetization is along the c-axis" while saying "along z" does not really mean anything.



Best regards,



Leandro

________________________________
From: Wien <wien-bounces at zeus.theochem.tuwien.ac.at> on behalf of Zhu, Jianxin <jxzhu at lanl.gov>
Sent: Friday, April 6, 2018 10:15:45 PM
To: A Mailing list for WIEN2k users
Subject: Re: [Wien] Magnetization axis, SOC, and rotation

Dear Leandro and Peter,

Thanks for bringing this question up.
Do I understand correctly that the direction like (001) in initso_lapw is defined with respect to the Cartesian coordinate?
As such, when we say (001),  it really means the magnetic moment axis is along the z-axis, rather than the primitive  Bravais vectors or conventional unit cell vectors.

Thanks,

Jianxin


From: Wien <wien-bounces at zeus.theochem.tuwien.ac.at> on behalf of Leandro Salemi <leandro.salemi at physics.uu.se>
Reply-To: A Mailing list for WIEN2k users <wien at zeus.theochem.tuwien.ac.at>
Date: Friday, April 6, 2018 at 8:35 AM
To: A Mailing list for WIEN2k users <wien at zeus.theochem.tuwien.ac.at>
Subject: Re: [Wien] Magnetization axis, SOC, and rotation




Dear Professor Blaha,



Thank you very much for your answer.

I've looked and those angles are given in the case.scfso (2nd line) !



Best regards,



Leandro





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