Spectroscopic Parameters of 15 Low-Lying Doublet and Quartet Λ-S States as Well as 36 Ω States of VO

A large number of experimental transitions between Ω states of VO have been observed. However, almost no theoretical calculations are currently available in the literature, in which the spin-orbit coupling effect on the spectroscopic parameters of VO was computed. In this work, the PECs of X 4 Σ – , A′ 4 Φ, A 4 Π, B 4 Π, C 4 Σ – , D 4 Δ, a 2 Σ – , b 2 г, c 2 Δ, d 2 Σ + , e 2 Φ, f 2 Π, g 2 Π, 2 2 Φ, and 3 2 Π states as well as their 36 Ω states were computed through internally contracted multireference configuration interaction approach with Davidson modification. To improve the accuracy of spectroscopic parameters, scalar relativistic and core-valence correlation correlations were included by aug-cc-pwCV5Z-DK and aug-cc-pCV5Z-DK basis sets for V and O, respectively. The spectroscopic parameters of 15 Λ-S and 36 Ω states were evaluated. The c 2 Δ, f 2 Π, g 2 Π, and 3 2 Π states were found to be inverted with the spin-orbit coupling effect taken into account. The splitting energies between the two neighboring Ω states from the A 4 Π –1/2 to A 4 Π 5/2 states were 34.89, 40.61, and 46.52 cm –1 ; those from the B 4 Π –1/2 to B 4 Π 5/2 states were 61.23, 62.11, and 64.75 cm –1 ; those from the D 4 Δ 1/2 to D 4 Δ 7/2 states were 88.16, 104.20, and 107.95 cm –1 , and those from the A′ 4 Φ 3/2 to A′ 4 Φ 9/2 were 192.73, 175.80, and 168.43 cm –1 , which compared well with the available experimental results, indicating that these results achieved high quality. It is expected that these spectroscopic parameters would provide some useful guidelines for future studies.