[Wien] A general question about Spin Polarized calculation/materials

[Qiwen YAO]

Dear Gerhard,
Thank you for your reply and your help.
Can I ask you one more question in this regard so to get a clearer understanding in this:

Say I have done calculation to one ABO3 structure and the Spin polarized result was that it was Spin Up in 5 states/eV/f.u. and 0 states in spin down, and then I have done an another calculation to a totally different and non related structure A'B'2, for example, and I obtained the Spin Polarized result as 0 in spin up state and 5 states/eV/f.u. spin down (note: Wien2k result for the 2nd compound is spin down polarized).

So between ABO3 and A'B'2, can I say that these two different compounds is always spin polarized in opposite way but with the same magnitude of DOS? And if I am to be able to have a machine to measure their polarization and I always obtain opposite results - one is negative and the other is positive but with the same magnitude? Or if it is meaningless to compare the spin polarization of these two compounds?

Thank you,
Wen



------Original Message------
From:"Gerhard Fecher"<fecher at uni-mainz.de>
To:"A Mailing list for WIEN2k users"<wien at zeus.theochem.tuwien.ac.at>
Cc:
Subject:Re: [Wien] A general question about Spin Polarized calculation/materials
Date:10/07/2011 06:55:31 AM(+0000)
>Read a textbook about magnetism to find how the magnetic moments of diamagnetic, paramagnetic, or ferromagnetic
>materials are oriented when a external magnetic field is applied.
>
>Spin up and spin down have in the calculations principally no meaning they are just used to distinguish
>electrons with different spin.
>Try Fe for example, if you do 2 calculations one with initial spin up and one with initial spin dn,
>you should receive identical results just with the spin up and down density of states interchanged,
>that is one will have a negative magnetic moment.
>If you define correctly majority and minority electrons (instead of up/dn)  then you will have in both cases a positive magnetic moment.
>
>
>
>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;Qiwen  YAO [Yao.Qiwen at nims.go.jp]
>Gesendet: Freitag, 7. Oktober 2011 03:17
>Bis: A Mailing list for WIEN2k users
>Betreff: [Wien] A general question about Spin Polarized calculation/materials
>
>Dear Wien2k users,
>I am wondering if there is a specific/practical way to measure/differentiate whether a spin polarized material is spin up or spin down - apart from using a software like Wien2k's calculation to achieve the result?
>
>I know that we can obtain such a result for a solid state material via the spin polarized calculation using Wien2k - and via Wien2k we can also find out the material's over all spin polarized state (via the Total DOS, for example) if it is spin up or spin down. But I keep wondering: how do we tell and in what way can I say a spin polarized calculation result is meaningful/significant to practical applications - in a practical or measurable way?
>
>Thank you,
>Wen
>
>**********************************************************
>
>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
>
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**********************************************************

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

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