Term: microcanonical rate constant https://doi.org/10.1351/goldbook.M03896 Definition: A rate constant calculated by microcanonical variational transition-state theory and therefore a rate constant that relates to a fixed energy. Related Terms: 1) rate constant (http://doi.org/10.1351/goldbook.O04322). 2) microcanonical variational transition-state theory (http://doi.org/10.1351/goldbook.M03897). Source: PAC, 1996, 68, 149. 'A glossary of terms used in chemical kinetics, including reaction dynamics (IUPAC Recommendations 1996)' on page 173 (https://doi.org/10.1351/pac199668010149) Citation: 'microcanonical rate constant' 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.M03896 License: 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. Disclaimer: 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.