Hund's cases

In rotational-vibrational and electronic spectroscopy of diatomic molecules, Hund's coupling cases are idealized descriptions of rotational states in which specific terms in the molecular Hamiltonian and involving couplings between angular momenta are assumed to dominate over all other terms. There are five cases, proposed by Friedrich Hund in 1926-27^[1] and traditionally denoted by the letters (a) through (e). Most diatomic molecules are somewhere between the idealized cases (a) and (b).^[2]

^ Aquilanti, V.; Cavalli, S.; Grossi, G. (1996). "Hund's cases for rotating diatomic molecules and for atomic collisions: angular momentum coupling schemes and orbital alignment". Zeitschrift für Physik D. 36 (3–4): 215–219. Bibcode:1996ZPhyD..36..215A. doi:10.1007/BF01426406. S2CID 121444836.
^ Brown, John M.; Carrington, Alan (2003). Rotational Spectroscopy of Diatomic Molecules. Cambridge University Press. ISBN 0521530784.

[1] Aquilanti, V.; Cavalli, S.; Grossi, G. (1996). "Hund's cases for rotating diatomic molecules and for atomic collisions: angular momentum coupling schemes and orbital alignment". Zeitschrift für Physik D. 36 (3–4): 215–219. Bibcode:1996ZPhyD..36..215A. doi:10.1007/BF01426406. S2CID 121444836.

[brown-2] Brown, John M.; Carrington, Alan (2003). Rotational Spectroscopy of Diatomic Molecules. Cambridge University Press. ISBN 0521530784.

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