THE E3-SIGMA--A3-PI(0,0) AND E1-SIGMA--A'1-PI(0,0), (1, 1), AND (2, 2) BANDS OF CAO - MULTISTATE DEPERTURBATION OF THE E3-SIGMA-(V=O) - C3-SIGMA+(V=1) - E1-SIGMA-(V=O) SYSTEM

The experimental study and analysis of the e3Σ--a3Π(0, 0) and E1Σ--A′ 1Π(0, 0), (1, 1), and (2, 2) Orange-Band transitions of CaO are presented along with a deperturbation analysis of the e3Σ- (v = 0) ∼ c3Σ+ (v = 1) ∼ E1Σ- (v = 0) complex of spin-orbit interacting, Aππ-1 configuration, electronic states. Use of laser-induced fluorescence, sub-Doppler intermodulated fluorescence, and optical-optical double-resonance techniques allowed the determination of accurate molecular constants for the e3Σ- (v = 0) and E1Σ- (v = 0, 1, 2) states as well as their common perturber, c3Σ+ (v = 1). Based on an integer-valence, single-atomic-ion configuration, ligand field model of the structure of the low-lying electronic states of CaO, in which the monovalent CaF structure is used as a model for Ca+ localized orbitals and the monovalent NaO structure is used for O- localized orbitals, predictions of several interstate interactions compare favorably with experimentally determined interaction parameters. The discussions of interactions include treatments of diagonal and off-diagonal spin-orbit interactions in Π and Σ electronic states, lambda doubling in 1Π and 3Π states, and fine structure in 3Σ states. Analyses of interactions between O- p σ-1 and pπ-1 configuration states, which differ in re by ∼5%, required the introduction of an empirical factor, Θ, which is interpreted as a measure of hybridization in atomicion orbitals. © 1990.