I am used to setting up calculations with spins set to be parallel or 
antiparallel to each other and I would probably class those set up with 
antiparallel spins as AFM. You can also set up calculations that don't include 
spin and so will not have any magnetic moments. I tend to regard these as 
nonmagnetic calculations. However I take the point that something set up as AFM 
could turn out to have a 0 magnetic moment. 

Sorry you are right it should be the V magnetic moments that balance out. 

A Pauli paramagnet should have 0 magnetic moment from these calculations (it 
could be antiferromagnetic or nonmagnetic) as the magnetic moment is only 
produced when a magnetic field is applied.

-----Original Message-----
From: Wien [mailto:wien-boun...@zeus.theochem.tuwien.ac.at] On Behalf Of 
Fecher, Gerhard
Sent: 07 September 2017 10:39
To: A Mailing list for WIEN2k users
Subject: Re: [Wien] About the magnetic moment of vanadium in vanadium sulphide

Sorry but there is obviously a lot of nonsense in the comments where you should 
first think about:

Please explain why a spin polarized calculation will always result in a 
ferromagnetic (or antiferromagnetic) state ? How do you define a ferromagnet 
(or antiferromagnet) ?  
What happens when the magnetic part of the Hamilton becomes Zero in a spin 
polarized calculation ? What is a ferromagnet or antiferromagnet without 
magnetic moments at the atoms ?
Why should a paramagnet become an antiferromagnet in the calculation ?

Why is VS an antiferromagnet when V has a magnetic moment of 0.05 muB and S one 
of -0.05 muB ? Don't you think it is possible that the magnetisation of two V 
atoms may have to cancel ?

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-boun...@zeus.theochem.tuwien.ac.at] im Auftrag von E.A.Moore 
[e.a.mo...@open.ac.uk]
Gesendet: Donnerstag, 7. September 2017 11:02
An: A Mailing list for WIEN2k users
Betreff: Re: [Wien] About the magnetic moment of vanadium in vanadium sulphide

I have been following this thread and I think there is some confusion.

1. On the thread it said that the experiment showed it was Pauli paramagnetic. 
This is the type of magnetism displayed by some metals e.g. sodium which is 
only apparent if you apply a magnetic field.

2. If you include spin in your calculation (GGA or GGA + U) you can only get 
ferromagnetic, antiferromagnetic or ferromagnetic states. (An earlier thread 
deals with how to get paramagnetic states). I think you can only get a 
nonmagnetic state if you do not include spin? A material with Pauli 
paramagnetism will be antiferromagnetic in straight forward spin-including 
calculations.

3. I assume the 0.05 muB refers to the magnetic moment on V. If vanadium 
sulphide is antiferromagnetic and the magnetic moment on Vanadium is 0.05 muB, 
then there must be a balancing magnetic moment on the sulphur.

4. I suspect this compound might be alloy-like. Is there considerable mixing of 
V and S in the valence bands?

5. Assuming your formula is VS, it might be worth noting that VO shows some 
metallic physical properties.

Elaine A. Moore
Reader in theoretical chemistry
The Open University



-----Original Message-----
From: Wien [mailto:wien-boun...@zeus.theochem.tuwien.ac.at] On Behalf Of 
Fecher, Gerhard
Sent: 07 September 2017 08:12
To: A Mailing list for WIEN2k users
Subject: Re: [Wien] About the magnetic moment of vanadium in vanadium sulphide

0.05 muB does not mean that it is antiferromagnetic ! what was your charge 
convergence criterion ?

You did never answer my question whether you started the EECE calculation from 
a converged GGA calculation.

Why do you like to have an afm state when the experiment tells it is not ?

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-boun...@zeus.theochem.tuwien.ac.at] im Auftrag von Abderrahmane 
Reggad [jazai...@gmail.com]
Gesendet: Donnerstag, 7. September 2017 00:26
An: wien@zeus.theochem.tuwien.ac.at
Betreff: Re: [Wien] About the magnetic moment of vanadium in vanadium sulphide

Hi Martin

The problem is that I want to know if it's possible to get a such value of 0.05 
MB for atomic magnetic moment for the AFM state of vanadium sulphide in NiAs 
structure.

Hafner and Hobbs have found all the calculations converged to the non magnetic 
state because they have used the GGA method. To get the AFM state they have to 
use either the EECE or GGA+U methods.

I hope you touch the problem


Best regards
_______________________________________________
Wien mailing list
Wien@zeus.theochem.tuwien.ac.at
http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien
SEARCH the MAILING-LIST at:  
http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html
-- The Open University is incorporated by Royal Charter (RC 000391), an exempt 
charity in England & Wales and a charity registered in Scotland (SC 038302). 
The Open University is authorised and regulated by the Financial Conduct 
Authority in relation to its secondary activity of credit broking.
_______________________________________________
Wien mailing list
Wien@zeus.theochem.tuwien.ac.at
http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien
SEARCH the MAILING-LIST at:  
http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html
_______________________________________________
Wien mailing list
Wien@zeus.theochem.tuwien.ac.at
http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien
SEARCH the MAILING-LIST at:  
http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html
_______________________________________________
Wien mailing list
Wien@zeus.theochem.tuwien.ac.at
http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien
SEARCH the MAILING-LIST at:  
http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html

Reply via email to