[Wien] Ferromagnetic compound has non-magnetic moments

[Fecher, Gerhard]

what is the magnetic moment per Ni atom and the total magnetic moment per cell from the experiment ? (any reference available ?)
what type of "magnetic" does the experiment find: ferro-, ferri-, antiferro-magnetic, spiral spin structure or any other noncollinear spin structure ?

Was your initial magnetisation set up correctly ?

If your initial solution was not spin polarized and you use it for further methods, then the addition of SO (for example) will not result in a spin polarized solution. (Why should it ?)

Did you try to start with a fixed spin moment calculation using the total magnetic moment per cell from the experiment ? 
Were the Fermi energies of the two spin channeds from this calculations close to each other, or does it need a large field to stabilize the solution ?

By the way, there is no need that intermetallic compounds have both, itinerant and localized magnetism.
Indeed, LDA+U does not make sense if you do not have localized electrons.

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 Tim Hackett [thackett1992 at gmail.com]
Gesendet: Montag, 12. Juni 2017 20:01
An: A Mailing list for WIEN2k users
Betreff: Re: [Wien] Ferromagnetic compound has non-magnetic moments

Dear Xavier,

Thank you for your quick reply.  Yes, the compound is metallic experimentally in the full temperature range from 300K to 2K.

Sincerely,

Tim H.

On Mon, Jun 12, 2017 at 12:48 PM, Xavier Rocquefelte <xavier.rocquefelte at univ-rennes1.fr<mailto:xavier.rocquefelte at univ-rennes1.fr>> wrote:

Dear Timothy

The main problem here is that in such intermetallic compound you must have both itinerant and localized magnetisms which is not so trivial to treat from DFT and adding an Hubbard correction will not help. To my point of view the problem can be solved by looking at the experimental data to better understand which kind of magnetic properties are expected. Is the compound metallic?

Best wishes

Xavier

Le 12/06/2017 à 18:39, Tim Hackett a écrit :
Greetings Prof. Blaha and all WIEN2k community,

I have a compound which consists of 29 atoms and is made up of Nb-Ni-B [Mg3Ni20B6-type, cF116, Fm•3m (No. 225)] that has been found experimentally to be magnetic.

But in my WIEN2k calculations using GGA and GGA+U with and without SO coupling, I found almost zero moment on each element with all formalism.

I used an RKmax = 7.5 in case.in1 (as per suggestion in the FAQ), 1000 k points (I also used 2000 and there is no difference) and I converged with at least 10^-6 for both energy and charge criteria.

I searched extensively through the mailing list and have found no solution on this issue.

Please suggest how can I improve my calculations to match the experimental finding.

Best Regards-
--

Timothy A. Hackett

Assistant Scientist I

Division of Materials Science & Engineering

Ames Laboratory, Iowa State University, Ames, IA 50011



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--

Timothy A. Hackett

Assistant Scientist I

Division of Materials Science & Engineering

Ames Laboratory, Iowa State University, Ames, IA 50011

515/724-1762 thackett1992 at gmail.com<mailto:thackett1992 at gmail.com>