Term: activation energy (Arrhenius activation energy)
https://doi.org/10.1351/goldbook.A00102

Definition:
An empirical parameter characterizing the exponential temperature dependence of the rate coefficient, k, Ea = RT^2.(d(lnk)/dT), where R is the gas constant and T the thermodynamic temperature. The term is also used for threshold energies in electronic potential surfaces, in which case the term requires careful definition.

Related Terms:
1) rate coefficient (http://doi.org/10.1351/goldbook.R05137).
2) gas constant (http://doi.org/10.1351/goldbook.G02579).
3) thermodynamic temperature (http://doi.org/10.1351/goldbook.T06321).
4) threshold energies (http://doi.org/10.1351/goldbook.T06366).

Source: Green Book, 2nd ed., p. 55 (https://goldbook.iupac.org/files/pdf/green_book_2ed.pdf)

Citation: 'activation energy (Arrhenius activation energy)' 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.A00102

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