Asymptotic Interactions Between Open Shell Partners in Low Temperature Complex Formation: The H(X2S1/2) + O2 (X3∑ g − ) and $$ O({}^3P_{j_O } ) + OH(X^2 \Pi _{\tilde \Omega } )$$ Systems

The asymptotic interactions at large intermolecular distances are determined for two open-shell systems, H(X2S1/2) + O2 (X3∑{skg/−}) and \( O({}^3P_{j_O } ) + OH(X^2 \Pi _{\tilde \Omega } )\) for fixed values of intramolecular distances r. The electronic diabatic Hamiltonians are set up for two purposes: i) the direct diagonalization of the electronic Hamiltonian yielding two-dimensional potential energy surfaces (PES) which depend on the intermolecular distance R and the angle γ. between R and r, and ii) the incorporation of the diabatic electronic basis into the diabatic roronic basis which can be used in the construction of the roronic Hamiltonian in the total angular momentum representation. The former procedure allows one to compare the asymptotic PES with their ab initio counterparts, while the latter provides the input data for the calculation of low temperature capture rate constants within the statistical adiabatic channel model (SACM).