04238 IUPAC Gold Book - nuclear quadrupole moment 10.1351/goldbook.N04238 N04238 current 1 A parameter which describes the effective shape of the equivalent ellipsoid of the nuclear charge distribution, \(Q>0\) for prolate (e.g. $\ce{^{57}Fe}$, $\ce{^{19}7Au}$); \(Q nuclei https://goldbook.iupac.org/terms/view/N04256 PAC, 1976, 45, 211. 'Nomenclature and Conventions for Reporting Mössbauer Spectroscopic Data' on page 214 (https://doi.org/10.1351/pac197645030211) https://goldbook.iupac.org/terms/view/N04238/html https://goldbook.iupac.org/terms/view/N04238/json https://goldbook.iupac.org/terms/view/N04238/plain Citation: 'nuclear quadrupole moment' 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.N04238 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. 2026-08-09T15:34:04+00:00