## collision efficiency, $$B_{\text{c}}$$

Synonym: de-energization efficiency
https://doi.org/10.1351/goldbook.C01164
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
C01164.png
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.
Source:
PAC, 1996, 68, 149. (A glossary of terms used in chemical kinetics, including reaction dynamics (IUPAC Recommendations 1996)) on page 159 [Terms] [Paper]