reaction probability, P r

The probability that a reaction occurs when two particles undergo a collision. If $N c$ is the number of collisions occurring in unit time, and $N r$ the number of reactions occurring in unit time: $P r = N r N c$ .

Source:

PAC, 1996, 68, 149 (A glossary of terms used in chemical kinetics, including reaction dynamics (IUPAC Recommendations 1996)) on page 184