Upper state molecular constants for the (0, 0, 3) and (1, 0, 3) vibration-rotation bands of nitrogen dioxide
High-resolution absorption spectra of the (0,0,3) and (1,0,3) vibration-rotation bands of 14N 16O 2 and 15N 16O 2 were analyzed. Initial values for the ground state constants and predicted values of A, B, and C for the upper states of the (0,0,3) and (1,0,3) bands were taken from previous work. Improved values of the upper state constants including centrifugal distortion and empirical P6 terms have been obtained. Further refinement of the ground state constants was not possible. Spin splitting was observed and analyzed for a number of transitions in the (0,0,3) band of both isotopes. Effective spin-rotation coupling constants were obtained for the excited states. Due to the weakness of absorption and lack of resolution no spin splitting was observed in the (1,0,3) bands.