Accurate calculations of spectroscopic properties for the 13 Λ–S states and the 23 Ω states of BO radical including the spin–orbit coupling effect

Abstract

The spectroscopic properties of 23 Ω states generated from the 13 Λ–S states of BO radical are studied for the first time for internuclear separations from about 0.07 to 1.0nm. Of the 13 Λ–S states, each of the F2Π, 12Φ and 12Δ states is found to possess the double well. Each of the 14Π, C2Π, 12Σ− and 22Σ− states possesses one well with one barrier. The A2Π, 14Π and F2Π are the inverted states with the spin–orbit coupling effect taken into account. All the states possess the deep well except for the 12Φ. The potential energy curves (PECs) are calculated by the complete active space self-consistent field method, which is followed by the internally contracted multireference configuration interaction approach with the Davidson correction. Core–valence correlation and scalar relativistic corrections are included into the calculations. The PECs are extrapolated to the complete basis set limit. The spin–orbit coupling effect is accounted for by the state interaction approach with the Breit–Pauli Hamiltonian. The spectroscopic parameters are evaluated, and compared with the available measurements and other theoretical results. The Franck–Condon factors and radiative lifetimes of the transitions from the B2Σ+, C2Π, D2Σ+, 12Σ− and 14Π Λ–S states to the ground state are calculated for several low vibrational levels, and some necessary discussion is made. Analyses show that the spectroscopic parameters reported in this paper can be expected to be reliably predicted ones.