The spin angular momentum is given by
where is the spin quantum number and is h-bar. The z-component of spin angular momentum is then
where
Intersystem Crossing, Orbital Angular Momentum, Spin Magnetic Dipole Moment, Spin Quantum Number, Total Angular Momentum
References
Eisberg, R. and Resnick, R. Quantum Physics of Atoms, Molecules, Solids, Nuclei, and Particles, 2nd ed. New York: Wiley, 1985.
Varshalovich, D. A.; Moskalev, A. N.; and Khersonskii, V. K. "Spin Angular Momentum Operator." §2.3 in Quantum Theory of Angular Momentum. Singapore: World Scientific, pp. 42-43, 1988.
