RRKM
The Rice–Ramsperger–Kassel–Marcus (RRKM) theory is a theory of chemical reactivity.[1][2][3] It was developed by Rice and Ramsperger in 1927[4] and Kassel in 1928[5] (RRK theory[6]) and generalized (into the RRKM theory) in 1952 by Marcus[7] who took the transition state theory developed by Eyring in 1935 into account. These methods enable the computation of simple estimates of the unimolecular reaction rates from a few characteristics of the potential energy surface.