Example: chain initiation reaction O₂+C₂H₆ -> HO₂+C₂H₅

The reaction O2+C2H6->HO2+C2H5 is one of chain-initiation reactions in the practically important process of hydrocarbon low-temperature combustion. The rate constant of this reaction was evaluated using the transition state theory. The parameters of the potential surface were evaluated by quantum-chemical calculations at the DFT level of theory using the Gaussian-98 program package. The results of calculations of the rate constant are presented in the figure along with the available experimental data. It can be seen that the transition state theory with the parameters obtained from quantum-chemical calculations provides the quantitative description of the bimolecular reaction involving a polyatomic molecule.