Potential energy curves and spectroscopic parameters of the 24 Λ-S states and 54 Ω states of the F2+ cation including the spin-orbit coupling effect

This work calculated the PECs of 24 Λ -S states and 54 Ω states of F 2 + cation. The calculations were done with the CASSCF method, which was followed by the internally contracted MRCI approach. Core-valence correlation correction, scalar relativistic correction and basis set extrapolation were taken into account. Of these 24 Λ -S states, the 2 2 Σ g − , 2 2 Σ u − , 2 4 Σ g − , 1 4 Δ u , and 2 4 Π g states were found to be repulsive. The X 2 Π g , A 2 Π u 1 4 Δ g , 1 4 Π g and 2 4 Π g states were found to be inverted with the spin-orbit coupling effect included. The 1 2 Δ g , 2 4 Π u , 1 4 Π g , 1 4 Σ u + , 2 2 Π u , 1 4 Σ g − , 2 4 Σ u − , and 1 2 Σ g + states were found to be weakly bound. The 2 4 Σ u − state had double wells. The avoided crossings of PECs were observed between the A 2 Π u and 2 2 Π u states, the X 2 Π g and 2 2 Π g states, the 1 2 Σ u − and 2 2 Σ u − states, the 1 4 Π u and 2 4 Π u states, and the 1 4 Σ − g and 2 4 Σ − g states. Some spectroscopic parameters were determined and the vibrational properties of several weakly-bound states were predicted. The spin-orbit coupling effect on the spectroscopic parameters was evaluated. Comparison with available experimental data shows that the methodology used in this paper is highly accurate for this system.