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[Matthieu Verstraete <mjv500@york.ac.uk>]

Formally the spin is not a well defined quantity once you add spin orbit 
interaction. The spinor wavefunctions all have both spin up and spin down 
components, and you can't define the actual spin of the system, only the 
expectation value of the z Pauli matrix (as I recall this is not output 
in abinit, but is a natural byproduct). Obviously, this depends on your 
choice of axes!

The eigenfunctions for bands which are "spin degenerate" will be doubled. 
Others will have the "spin degeneracy" lifted, but that doesn't mean one 
band is spin up and the other spin down. Both are spinorial.

Matthieu


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Dr. Matthieu Verstraete                 mailto:mjv500@york.ac.uk
Dept. of Physics, University of York,     tel: +44 1904 43 22 08
Heslington, YO10 5DD York, United Kingdom fax: +44 1904 43 22 14