Adiabatic PECs of doublet (panel a; 1–5 ²Σ⁺: red line, 1–7 ²Π: blue line, 1 ²Φ: violet line, 1–3 ²Δ: black line, 1–3 ²Σ⁻: green line), quartet (panel b; 1–2 ⁴Σ⁺: red line, 1–4 ⁴Π: blue line, 1–2 ⁴Δ: black line, 1–3 ⁴Σ⁻: green line), and sextet (1 ⁶Σ⁺: brown line, 1 ⁶Π: violet line) spin states of CO⁺ molecular ion as a function of internuclear distance R. All are given in atomic units (a.u.).