THEORETICAL-STUDY OF THE NO BETA-SYSTEM

Ab initio calculations including high levels of correlation treatment have been performed for the B2-PI-X2-PI-beta system of NO. The calculations are complicated by the fact that the B2-PI state gains considerable Rydberg character in the Franck-Condon region of this transition, as it approaches an avoided crossing with the C2-PI Rydberg state at shorter r values. The calculated lifetimes vary from 2.12 to 1.17-mu-s for v' = 0 to 6, as compared with the recent measurements using laser induced fluorescence that vary from 2.00 to 0.85-mu-s. Nearly exact agreement with the experimental lifetimes can be achieved by shifting the transition moment function to larger r values to simulate a more rapid onset of the Rydbergization of the B2-PI state. The calculated Einstein coefficients for v' = 6 to v" = 0-16 are in overall good agreement with experiment, but systematic differences remain that may be partially attributable to limitations in the calibration of the spectrometer.