MILLIMETER-WAVE OPTICAL DOUBLE RESONANCE SPECTRA OF $NO_{2}$: IS N A GOOD QUANTUM NUMBER?

These experiments were performed at the Harrison Regional Spectroscopy Laboratory, Massachusetts Institute of Technology, Cambridge, Mass. 02139. Address of Coy: Dept. of Chemistry, Harvard University, Cambridge, Mass. 02138. Address of Lehmann: Dept. of Chemistry, Princeton University, Princeton. N. J. 08544 Address of Delucia: Dept. of Physics, Duke University, Durham, N. C. 27706.