[Wien] spin density

[Javad hashemifar]

Hello
If I correctly understood your question, you are speaking about the
magnetic moments (difference between spin up and down charges). Why
you expect that your magnetic moments should be integer. Except some
special group of materials the magnetic moments are not integer due to
the partial filling of some states. If all of the bands in a system
are completely occupied or unoccupied then you would have integer
magnetic moments. This situation happens in some ferromagnetic
materials like half metals that in one spin channel (say up spin) have
metallic behavior while in the other one (say down spin) are
semiconductor. Therefore the bands in down channel are completely
occupied leading to an integer number of the total down electrons.
since the total number of electrons are integer hence the number of up
electrons and accordingly the magnetic moments will be integer.
But as it was mentioned due to the partial filling of some bands, in
general, magnetic moments are not integer.

Regards
SJ Hashemifar

On 11/15/06, Indrajit Bandyopadhyay <indrajit.bandyopadhyay at gmail.com> wrote:
> Dear All,
>
> I have a question regarding spin density in
> collinear magnetic calculation. I searched in
> the archive for an answer to my question, but
> could not find. The question is: Is it possible
> to obtain the difference between spin-up and spin-dn
> charge nonintegral (say 0.56, 3.48) instead of integers?
> In what circumstances, I may expect that situation?
> Is it due to occupancy of ghost bands i.e. bands whose
> energies Ei > Ef (Fermi energy).
>
> Thanks a lot for your answers,
>
> Indrajit
>
> _______________________________________________
> Wien mailing list
> Wien at zeus.theochem.tuwien.ac.at
> http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien
>
>
>


-- 
===========================
Javad Hashemifar, Ph.D. student
Tel:  +98-311-3912375
Fax: +98-311-3912376
Physics Department, Isfahan University of Technology, 84156, Isfahan, Iran
--------------------------------------------------------------
Please DO NOT send email to my yahoo address: jhashemifar at yahoo.com
It is going to be disabled