[Wien] Discrepancy in the simulation of the paramagnetic state

[Xavier Rocquefelte]

Just to add one more point to this funny discussion, the term 
"paramagnetic" is sometimes used in the DFT litterature in an improper way.

It could clearly lead to misunderstanding for researchers who do not 
know so much on how magnetic properties could evolve with temperature 
and applied magnetic field. When you see in a paper "paramagnetic state" 
simulated using DFT ... it is NOT paramagnetic at all, it is simply a 
trick which must be considered with care as previously mentionned by 
Peter, Eliane and Martin.

If you want to simulate a paramagnetic state you need to include the 
temperature effects, i.e. you should consider the spin dynamics and the 
competition between magnetic exchange interactions and thermal 
fluctuations. This could be done, at least, using Monte-Carlo 
calculations based on an effective hamiltonian constructed on top of DFT 
parameters (including magnetic exchange and anisotropy at least).

Best Regards

Xavier




Le 27/11/2016 à 10:01, Fecher, Gerhard a écrit :
> How do you distinguish a diamagnetic, a paramagnetic, a ferromagnetic, and an antiferromagnetic state.
>
> Think !
>
> This will answer your question, hopefully.
>
> Ciao
> Gerhard
>
> DEEP THOUGHT in D. Adams; Hitchhikers Guide to the Galaxy:
> "I think the problem, to be quite honest with you,
> is that you have never actually known what the question is."
>
> ====================================
> Dr. Gerhard H. Fecher
> Institut of Inorganic and Analytical Chemistry
> Johannes Gutenberg - University
> 55099 Mainz
> and
> Max Planck Institute for Chemical Physics of Solids
> 01187 Dresden
> ________________________________________
> Von: Wien [wien-bounces at zeus.theochem.tuwien.ac.at] im Auftrag von Abderrahmane Reggad [jazairdz at gmail.com]
> Gesendet: Samstag, 26. November 2016 22:30
> An: wien at zeus.theochem.tuwien.ac.at
> Betreff: Re: [Wien] Discrepancy in the simulation of the paramagnetic state
>
> Thank you Prof Blaha for your quick answer.
>
> The Ni atom is 3d transition metal . But my question is about the simulation of the paramagnetic state. There are many people that considere that the paramagnetic state is the non-spin polarierd one and the magnetic moment is zero, but you say no and the magnetic moments exist in arbitrary directions and my quoting is about that.
>
> I have given 2 examples for that discrepancy with your statement.
>
> Best regards
> --
> Mr: A.Reggad
> Laboratoire de Génie Physique
> Université Ibn Khaldoun - Tiaret
> Algerie
>
>
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