[Wien] A question regarding magnetic/spin calculation in Wien2k please

[Qiwen YAO]

Thank you very much for Xavier, Laurence and Fecher's responds. 
I think I can see a bigger picture about this issue now.

Grateful for the help.

Kind regards,
Wen


------Original Message------
From:"Fecher, Gerhard"<fecher at uni-mainz.de>
To:"A Mailing list for WIEN2k users"<wien at zeus.theochem.tuwien.ac.at>
Cc:
Subject:Re: [Wien] A question regarding magnetic/spin calculation in Wien2k please
Date:03/09/2012 05:36:37 PM(+0000)
>and not to forget, if the symmetry of the structure you use does not allow for antiferromagnetism then you will not find it.
>
>NOTE: Symmetry is everything 
>
>Ciao
>Gerhard
>
>
>====================================
>Dr. Gerhard H. Fecher
>Institut of Inorganic and Analytical Chemistry
>Johannes Gutenberg - University
>55099 Mainz
>________________________________________
>Von: wien-bounces at zeus.theochem.tuwien.ac.at [wien-bounces at zeus.theochem.tuwien.ac.at]&quot; im Auftrag von &quot;Laurence Marks [L-marks at northwestern.edu]
>Gesendet: Freitag, 9. März 2012 18:13
>An: A Mailing list for WIEN2k users
>Betreff: Re: [Wien] A question regarding magnetic/spin calculation in Wien2k    please
>
>Actually.... I have come across several cases where I started with a
>ferromagnetic state and it converged to non-magnetic or even
>antiferromagnetic, or the opposite. It does take a long time for it to
>change, so as Xavier says it is probably better to start from
>different minima.
>
>Note: the atomic positions can couple in to the spin-state, so you may
>need to do a full minimization not just a single set of atomic
>positions.
>
>On Fri, Mar 9, 2012 at 10:12 AM, Rocquefelte
><Xavier.Rocquefelte at cnrs-imn.fr> wrote:
>> If you start from a ferromagnetic situation, you will converge towards a
>> ferromagnetic state (I never encounter other situations).
>> However, it does not mean that you will find the global minimum in terms of
>> magnetic structure.
>> It simply means that you have converged the electronic density related to
>> the ferromagnetic configuration of your system (It will be a local minimum -
>> a metastable situation).
>>
>> To know which magnetic structure is the more stable, you should try
>> different magnetic ordering, or at least one ferromagnetic situation and few
>> antiferromagnetic situations (if possible). Then by comparing the total
>> energy of the different situations you will see which one is the more
>> stable.
>>
>> In the other hand, another way to estimate the magnetic interactions in a
>> system is to estimate the magnetic exchange couplings, J(ij), using a
>> mapping analysis (based on energy differences between different magnetic
>> orders). It will give you the nature of the magnetic interaction in all
>> directions and will help you to figure out what is the fundamental magnetic
>> state of your system.
>>
>> Best Regards
>>
>> Xavier
>>
>>
>>
>> On 03/09/2012 04:55 PM, Qiwen YAO wrote:
>>>
>>> Dear all,
>>> May I ask:
>>>
>>> is it correct to assume that the WIEN2k code will Optimizes the spin
>>> structure of a stucture/cell in ground state if, I choose spin-polarized
>>> calculation for the structure/cell from the beginning?
>>>
>>> What I mean is:
>>> for a compound, I only suspecting that it is magnetic and I have to
>>> include spin-polarization in the calculation, but I don't know wheather it
>>> is ferromagnetic, perfect-antiferromagentic or canted antiferromagnetic or
>>> even a mixed state of the magnetic status, so I would just do a
>>> spin-polarized calculation (selecting all the atoms in the cell to be
>>> spin-up from the beginning), then the resulting converged spin state would
>>> be the loweset energy state of the compound? - if that is a yes then it i
>>> s basically the case that, Wien2k sort it out itself and practically it
>>> was an Optimized spin structure for the compound in the ground state?
>>>
>>> Thank you for your time.
>>>
>>> Kind regards,
>>> Qiwen
>>>
>>> **********************************************************
>>>
>>> Dr QiWen YAO
>>> JSPS Fellow
>>> Multifunctional Materials Group
>>> Optical and Electronic Materials Unit
>>> Environment and Energy Materials Research Division
>>>
>>> National Institute for Materials Science
>>>
>>> 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, Japan
>>> Phone: +81-29-851-3354, ext. no. 6482, Fax: +81-29-859-2501
>>>
>>> **********************************************************
>>>
>>> _______________________________________________
>>> Wien mailing list
>>> Wien at zeus.theochem.tuwien.ac.at
>>> http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien
>>>
>>
>>
>> _______________________________________________
>> Wien mailing list
>> Wien at zeus.theochem.tuwien.ac.at
>> http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien
>
>
>
>--
>Professor Laurence Marks
>Department of Materials Science and Engineering
>Northwestern University
>www.numis.northwestern.edu 1-847-491-3996
>"Research is to see what everybody else has seen, and to think what
>nobody else has thought"
>Albert Szent-Gyorgi
>_______________________________________________
>Wien mailing list
>Wien at zeus.theochem.tuwien.ac.at
>http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien
>_______________________________________________
>Wien mailing list
>Wien at zeus.theochem.tuwien.ac.at
>http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien

**********************************************************

Dr QiWen YAO
JSPS Fellow
Multifunctional Materials Group
Optical and Electronic Materials Unit
Environment and Energy Materials Research Division

National Institute for Materials Science

1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, Japan
Phone: +81-29-851-3354, ext. no. 6482, Fax: +81-29-859-2501

**********************************************************