Complete active space self-consistent field potential energy surfaces, dipole moment functions, and spectroscopic properties of O3, CF2, NO - 2, and NF + 2

Three-dimensional potential energy and dipole moment surfaces have been calculated for the 24 electron triatomics O₃, CF₂, NO^-₂, and NF⁺₂ using complete active space self-consistent field wave functions (CASSCF) and a basis set of 87 (99 for NO^-₂) contracted Gaussian-type orbitals (cGTOs). The analytical potential energy functions (PEFs) have been used in perturbation and variational calculations of anharmonic spectroscopic constants and vibrational energy levels. The results for O₃ and CF₂ are compared to the available experimental data, and predictions of the rotational and vibrational spectra of NO^-₂ and NF⁺₂ have been made by comparison to these species. The equilibrium geometries of NO^-₂ and NF⁺₂ are predicted to be r_e=1.260 Å, θ_e=116.5° and r_e=1.242 Å, θ_e=108.0°, respectively. The fundamental vibrational frequencies (ν₁,ν₂,ν₃) and absolute band intensities (at 300 K) of these two ions are predicted to be 1286 cm^-1/31 cm^-2 atm^-1, 782 cm^-1/13 cm^-2 atm^-1, 1232 cm^-1/2900 cm^-2 atm^-1 (NO^-₂) and 1272 cm^-1/181 cm^-2 atm^-1, 711 cm^-1/25 cm^-2 atm^-1, 1210 cm^-1/1230 cm^-2 atm^-1 (NF⁺₂). Band intensities for several low-lying vibrational transitions have been calculated for all four species from the CASSCF dipole moment functions, and comparisons to experiment have been made for O₃ and CF₂.