The potential energy curves of the X ²Π_g, a ^{i 4}Π_u,_i a ²Π_u, b ⁴Σ_g^-, B ²Σ_g^-, ²Π_u, and c ⁴Σ_u^- states of O₂⁺ obtained...

Full title: The potential energy curves of the X ²Π_g, a ^{i 4}Π_u,_i a ²Π_u, b ⁴Σ_g^-, B ²Σ_g^-, ²Π_u, and c ⁴Σ_u^- states of O₂⁺ obtained using the muiticonfigurational spin tensor electron propagator method. With electron propagator methods, electronic ionization and attachment energies are obtained directly. The multiconfigurational spin tensor electron propagator method (MCSTEP) is explicitly designed for systems with open shell and/or nondynamical correlation in the initial state. We apply MCSTEP to O ₂ at several internuclear separations and obtain and report the MCSTEP potential energy curves and the spectroscopic constants for the X ²Π_g , α ⁴Π_u , A ²Π_u , b ⁴Σ_g^- , B ²Σ_g^- , ²Π_u, and c ⁴ΣΣ_u^- states of O ²⁺.