[Wien] RE How to do the different magnetic calculation for a material (for example:NiO)

[delamora]

Within WIEN2k a paramagnetic calculation is out of the range, you need;
WIENncm: a non-collinear magnetism version of WIEN2k
(written by Robert Laskowski )
New VERSION is out since 8. Juli 2008 !!!
----------
These type of calculations are quite computer demanding. We tried a simple case of tetrahedra, which has one non collinear solution with the moments pointing out of the tetrahedra (another is pointing in, etc.), this case needs only 4 independent magnetic atoms, using the Quantum Espresso and we had a poor result.

________________________________________
De: wien-bounces at zeus.theochem.tuwien.ac.at <wien-bounces at zeus.theochem.tuwien.ac.at> en nombre de apostnik at uni-osnabrueck.de <apostnik at uni-osnabrueck.de>
Enviado: miércoles, 24 de diciembre de 2014 09:14 a. m.
Para: A Mailing list for WIEN2k users
Cc: wien at zeus.theochem.tuwien.ac.at
Asunto: Re: [Wien] RE How to do the different magnetic calculation for a material (for example:NiO)

Dear A.Reggad:

if I remember correctly from textbooks on magnetism,
the paramagnetic substance contains local magnetic moments
which get aligned by external magnetic field, but tend to disorder
at temperature. Consequently, in order to simulate such a material
in a first-principle calculation, you need two essential elements:
i) a machinery to treat disorder (be it by choice of large enough
supercells and averaging over configurations, or, say, within
the coherent potential approximation), and ii) - not absolutely demanded
but often practical - an option in the code to treat noncollinear
magnetic moments. An example of recent calculation along this line
(an arbitrarily selected one among many other examples, that however
explicitly contains "paramagnetic" in the title): Phys.Rev.B 85, 144404.

Good luck

Andrei Postnikov


> Thanks Mr Delamora for your reply
>
> But I want to know how to do a paramagnetic calculation
>
> A paramagnetic calculation is a non magnetic one or not?
>
> Thanks
> --
> Mr: A.Reggad
> Laboratoire de Génie Physique
> Université Ibn Khaldoun - Tiaret
> Algerie
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