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

[Gerhard Fecher]

as I told, spin up and spin down don't tell you anything without knowing further details
one could have also called spin plus and spin minus, or simply minus and plus calculation as it just tells in which channel the the sB term is added
or subtracted from the potential just depending on the sign of the sB term.
You have to check what are the majority and what are the minority electrons

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]" im Auftrag von "Qiwen  YAO [Yao.Qiwen at nims.go.jp]
Gesendet: Freitag, 7. Oktober 2011 17:26
Bis: A Mailing list for WIEN2k users
Betreff: Re: [Wien] A general question about Spin Polarized     calculation/materials

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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