of the angular spin moment
along an arbitrary axis (usually chosen as the z-direction).
can take the values between
The term is also used to denote an operation (spin-symmetry projection) allowing one to eliminate spin contamination
in the cases where wavefunctions are not eigenfunctions of the operator
IUPAC. Compendium of Chemical Terminology, 2nd ed. (the "Gold Book"). Compiled by A. D. McNaught and A. Wilkinson. Blackwell Scientific Publications, Oxford (1997). XML on-line corrected version: http://goldbook.iupac.org (2006-) created by M. Nic, J. Jirat, B. Kosata; updates compiled by A. Jenkins. ISBN 0-9678550-9-8. doi:10.1351/goldbook