Three-dimensional nuclear dynamics on conically intersecting potential energy surfaces of O+3 (2A1–2B2)

Three-dimensional calculations of the nuclear dynamics of the ozone cation have been performed involving the vibronically coupled 2A1–2B2 electronic states and using the results of large-scale ab initio computations of Schmelz et al. [Chem. Phys. Lett. 183, 209 (1991)]. Anharmonic (diabatic) potential surfaces are employed and the vibronic coupling term is taken to be a linear function of the asymmetric stretch coordinate. These calculations are compared to the first and second bands of the experimental photoelectron spectrum. Most features of its peculiar shape can be correctly reproduced and interpreted in this way. The band maximum for zero temperature is assigned to the fourth peak and the first peak of the experimental spectrum is interpreted as a hot band (vibronic temperature ≊275 K). In addition the properties of a quadratic model Hamiltonian are investigated and compared to the afore mentioned calculations. It is found that the model Hamiltonian is suitable to reproduce the full three-dimensional computations. As a by-product of this work the vertical ionization potentials (IP) of the interacting states are determined to be IP(2A1)=12.78 eV and IP(2B2)=13.02 eV.