https://doi.org/10.1351/goldbook.P04811
@[email protected] in front of the exponential factor expressing the empirical temperature dependence of the @[email protected], \(k\), on temperature, \(T\),\(k=A\ \exp (- E_{\text{a}}/R\ T)\), where \(E_{\text{a}}\) is the @[email protected] energy.