05431 IUPAC Gold Book - Rydberg orbital 10.1351/goldbook.R05431 R05431 current 1 For an atom, an orbital with principal quantum number greater than that of any occupied orbital of the ground state. For a molecular entity, a molecular orbital which correlates with a Rydberg atomic orbital in an atomic fragment produced by dissociation. Typically, the extension of the Rydberg orbital is large compared to the size of the atom or molecular entity. dissociation https://goldbook.iupac.org/terms/view/D01801 ground state https://goldbook.iupac.org/terms/view/G02704 molecular orbital https://goldbook.iupac.org/terms/view/M03996 PAC, 1996, 68, 2223. 'Glossary of terms used in photochemistry (IUPAC Recommendations 1996)' on page 2272 (https://doi.org/10.1351/pac199668122223) https://goldbook.iupac.org/terms/view/R05431/html https://goldbook.iupac.org/terms/view/R05431/json https://goldbook.iupac.org/terms/view/R05431/plain Citation: 'Rydberg orbital' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. 10.1351/goldbook.R05431 The IUPAC Gold Book is licensed under Creative Commons Attribution-ShareAlike CC BY-SA 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) for individual terms. If you are interested in licensing the Gold Book for commercial use, please contact the IUPAC Executive Director at executivedirector@iupac.org . The International Union of Pure and Applied Chemistry (IUPAC) is continuously reviewing and, where needed, updating terms in the Compendium of Chemical Terminology (the IUPAC Gold Book). Users of these terms are encouraged to include the version of a term with its use and to check regularly for updates to term definitions that you are using. 2026-06-28T20:26:55+00:00