STIMULATED EMISSION PUMPING SPECTROSCOPY OF $^{2}\Sigma$ AND $^{2}\Pi$ VIBRONIC LEVELS IN $\bar{X} ^{2}\Pi$ NCO

Abstract

Renner Teller perturbed vibrational levels in $\tilde{X} ^{2}\Pi$ NCO have been accessed by the use of stimulated emission pumping following excitation of various levels in the $\tilde{A} ^{2}\Sigma^{+}$ state of the radical. All the levels of $^{2}\Pi$ symmetry associated with $v_{2} \leq 4$ and $v_{1} \leq 2$ have now been studied as well as those with $v_{3} \leq 3$. In addition, the pair of Fermi-resonant levels with $(v_{1}, v_{2}, v_{3}) = (110)$ and (030) which are of $^{2}\Sigma$ symmetry have also recently been studied. These data, together with the extensive high resolution studies of the radical by many previous workers provide an unprecedentedly large amount of information. We have determined harmonic and anharmonic potential function parameters and progress towards a global determination of the potential surface by direct inversion of the experimental data will be reported at the meeting. Acknowledgement: This research was carried out at Brookhaven National Laboratory under Contract No. DE-AC02-76CH00016 with the U. S.