Molecular Level-Crossing Spectroscopy: thegValue for an Excited State of Nitric Oxide

Zero-field level-crossing effects have been optically detected in the nitric oxide molecule by observing the change in intensity of molecular fluorescence from a specified state with magnetic field. The intensity follows an inverted Lorentzian with a field strength at half-maximum of 0.379±0.030 G. Together with the radiative lifetime as recently determined by Jeunehomme, this gives for the molecular $g$ factor for this level a value of 0.762±0.060. This places an upper limit on the magnitude of $\gamma$, the molecular $\rho$-type doubling constant, of $\left|\gamma \right|<~1.3\times {10}^{-5\mathrm{}}$ ${\mathrm{cm}}^{-1\mathrm{}}$ (390 KHz).