ANALYSIS OF THE [16.0]3-SIGMA--X3-SIGMA- AND [16.0]3-SIGMA--[4.3]3-PI-I BAND SYSTEMS OF THE NIO MOLECULE

The analysis of 13 electronic bands due to the NiO molecule is reported. Much of the visible spectrum of NiO in the 16 000-18 100 cm-1 region is assigned to transitions between the ground X3Σ- state and one excited state, which we name [16.0]3Σ-. Approximately 250 combination differences were fitted (RMS deviation 0.006 cm-1) to determine effective spin-spin and spin-rotation constants for the ground state, λ0 = 25.113 5(3) cm-1, γ0 = -0.243 81(6)cm-1. An extensive system of strong bands in the near-infrared is assigned as a [16.0]3Σ--[4.3]3Πi transition, and a thorough analysis of this low-lying 3Π state has also been possible. Approximately 300 combination differences were fitted (RMS deviation 0.07 cm-1) to determine these principal constants for [4.3]3Πi: T0 = 4 293.78(5) cm-1, Be = 0.497 1(2) cm-1, A0 = -349.21(5) cm-1, and ωe = 777.10(5). © 1992.