collision efficiency, \(B_{\text{c}}\)

Synonym: de-energization efficiency
The collision efficiency, or de-energization efficiency, is defined by: \[k_{\text{-1}} = B_{\text{c}}\ k_{\text{-1}}^{\text{sc}}\] where \(k_{-1}\) is the @O04322@ for a particular substance \(\text{M}\) when it brings about the de-energization process
and \(k_{-1}^{\text{sc}}\) is the corresponding @O04322@ for a reference molecule \(\text{M}_{\text{r}}\) that de-energizes \(\text{A}^{*}\) on every collision; that is, the reference molecule \(\text{M}_{\text{r}}\) undergoes @S06059@, and by definition has a collision efficiency \(B_{\text{c}}\) of unity. The species \(\text{A}^{*}\) is usually in a vibrationally-@E02257@, and \(\text{A}\) has energy less than that required for reaction to occur.
PAC, 1996, 68, 149. (A glossary of terms used in chemical kinetics, including reaction dynamics (IUPAC Recommendations 1996)) on page 159 [Terms] [Paper]