Often used with the same meaning as
sticking coefficient, but in principle it is a microscopic quantity concerned with the individual collision process.
Source:
PAC, 1976, 46, 71
(Manual of Symbols and Terminology for Physicochemical Quantities and Units - Appendix II. Definitions, Terminology and Symbols in Colloid and Surface Chemistry. Part II: Heterogeneous Catalysis)
on page 78