An electronic state
occuring as the initial or final state of a process involving the absorption or emission
of X-ray radiation. It represents a many-electron state which, in the purely atomic
case, has total angular momentum
) as a well defined quantum number.
PAC, 1991, 63, 735
(Nomenclature, symbols, units and their usage in spectrochemical analysis - VIII.
Nomenclature system for X-ray spectroscopy (Recommendations 1991))
on page 737
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. https://doi.org/10.1351/goldbook