Title: Rydberg transition
Long Title: IUPAC Gold Book - Rydberg transition
DOI: 10.1351/goldbook.R05432
Status: current

Definition
An electronic transition described approximately as promotion of an electron from a 'bonding' orbital to a Rydberg orbital. Spectral bands corresponding to Rydberg transitions approximately fit the Rydberg formula: \[\sigma = I - \frac{R}{(n\,-\,\mathit{\Delta })^{2}}\] where \(\sigma \) is the wavenumber, \(I\) the ionization potential of the atom or molecular entity, \(n\) a principal quantum number, \(R\) the Rydberg constant, and \(\mathit{\Delta}\) the quantum defect which differentiates between s, p, d, etc., orbitals. The notation used is, e.g. \(\pi \rightarrow \mathrm{ns}\).

Related Terms
- Rydberg constant: https://goldbook.iupac.org/terms/view/R05430
- Rydberg orbital: https://goldbook.iupac.org/terms/view/R05431
- ionization potential: https://goldbook.iupac.org/terms/view/I03208
- promotion: https://goldbook.iupac.org/terms/view/P04877

Source
- PAC, 1996, 68, 2223. 'Glossary of terms used in photochemistry (IUPAC Recommendations 1996)' on page 2272 (https://doi.org/10.1351/pac199668122223)

Other Outputs
- html: https://goldbook.iupac.org/terms/view/R05432/html
- json: https://goldbook.iupac.org/terms/view/R05432/json
- xml: https://goldbook.iupac.org/terms/view/R05432/xml

Citation: Citation: 'Rydberg transition' 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.R05432
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Accessed: 2026-06-28T18:57:04+00:00