Term: phase-space theory
https://doi.org/10.1351/goldbook.P04535

Definition:
This is a theory applied to unimolecular or bimolecular reactions proceeding through long-lived complexes. The probability of reaction is assumed to be proportional to the number of states available to a particular product channel divided by the number of states corresponding to all product channels. The theory is used to predict rates, product energy distributions, product velocity distributions, and product angular momentum distributions.

Related Terms:
1) unimolecular (http://doi.org/10.1351/goldbook.M03989-1).
2) probability (http://doi.org/10.1351/goldbook.P04855).
3) angular momentum (http://doi.org/10.1351/goldbook.A00353).
4) bimolecular (http://doi.org/10.1351/goldbook.M03989-2).
5) channel (http://doi.org/10.1351/goldbook.C00970).

Source: PAC, 1996, 68, 149. 'A glossary of terms used in chemical kinetics, including reaction dynamics (IUPAC Recommendations 1996)' on page 176 (https://doi.org/10.1351/pac199668010149)

Citation: 'phase-space theory' 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.P04535

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