Analysis of Dissociation—Recombination Processes for the CO2 Molecule with the Spin—Orbit Coupling Taken into Account

Abstract

The dissociation CO₂(X¹Σ) + M → CO(X¹Σ) + O(³P) + M and recombination CO(X¹Σ) + O(³P) + M → CO₂(X¹Σ) + M processes are considered with the spin—orbit coupling taken into account in the ground and several excited states of the CO₂ molecule. Because of the specific features of mutual position of potential energy surfaces of the CO₂ molecule in the ground and several excited states and the large values of spin—orbit interaction matrix elements, which causes the quantum nonadiabatic transition of the molecule from one state to another, these processes become effectively spin-allowed and the rate constants for the nonadiabatic reactions have large values. The proposed dissociation and recombination mechanisms include reactions involving singlet—triplet crossings.