) As previously defined, the transition event probability is directly related to the compatibility of configurations of the reactant and product system. Such compatibility is only reached for some configurations above the energy level 𝜀 ‡ (𝑞 ‡ ), and 𝜔(𝑞) is zero for any lower level. To obtain the total reaction rate 𝑟 one consequently only needs to integrate over all levels above 𝑞 ‡ : 𝓀 𝐵 𝑇 ) (17c) At chemical equilibrium, the reaction rate would become zero and I can define the equilibrium constant 𝐾 as the ratio between the number of elements present in the product or reactant system (Eq. 18a). 𝐾 is then a function of the characteristic degeneration functions of the reactant and product system and their respective ground state energy, while the superscript * denotes the total number of elements belonging to the reactant or product system in equilibrium. I can now rewrite 𝐾 using the currently unbeknown quantity 𝑋, defined by Eq. 18c. In the following section I will show that 𝑋 is precisely the (intensive) Gibbs Free energy of reaction.