Term: configuration (electronic)
https://doi.org/10.1351/goldbook.C01248

Definition:
A distribution of the electrons of an atom or a molecular entity over a set of one-electron wavefunctions called orbitals, according to the Pauli principle. From one configuration several states with different multiplicities may result. For example, the ground electronic configuration of the oxygen molecule (O2) is: 1σg2, 1σu2, 2σg2, 2σu2, 1πu4, 3σg2, 1πg2 resulting in the 3Σg, 1Δg and 1Σg+ multiplets.

Related Terms:
1) molecular entity (http://doi.org/10.1351/goldbook.M03986).
2) orbitals (http://doi.org/10.1351/goldbook.O04317).

Source: PAC, 1994, 66, 1077. 'Glossary of terms used in physical organic chemistry (IUPAC Recommendations 1994)' on page 1099 (https://doi.org/10.1351/pac199466051077)

Citation: 'configuration (electronic)' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. https://doi.org/10.1351/goldbook.C01248

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