THE D3-DELTA-I-A3-PI-I AND D3-DELTA-2-A1-PI SYSTEMS OF THE MGO MOLECULE

The 0-0 band of the d3Δ-a3Π transition of MgO lying at 372 nm has been observed at high-resolution by laser excitation spectroscopy. In addition, the 0-1, 1-2, and 2-3 bands of the 3Δ3-3Π2 subband and the 0-0 and 1-1 bands of the intercombination system d3Δ2-A1Π were also recorded. The rotational analysis of the observed bands and the global fit of all the available data relevant to the D, d1,3Δ states permit full characterization of the d3Δ state and derivation of accurate vibrational and rotational equilibrium constants (in cm-1) for the D, d1,3Δ states: {A table is presented}. Spin-orbit interaction between the d3Δ and the D1Δ states causes a large asymmetry of the d3Δ state spin-orbit components. It should be emphasized that since the spin-orbit (3Δ ∼ 1Δ) interaction was included in the 1,3Δ effective Hamiltonian matrix, the off-diagonal spin-orbit electronic parameter A(d3Δ ∼ D1Δ) was determined and the above constants are deperturbed". © 1991."