Knowledge Bank

Paramagnetic resonance absorption spectra of the OD radical $(X2\Pi 3/2)$ in the excited vibrational states has been observed at X-band frequencies. Analysis of the spectra gives the $\Lambda$-doubling frequencies $\nu \Lambda$, the molecular g-factors $gJ\pm$, and the hyperfine interaction constants as a function of vibrational states. $\nu \Lambda$ values are in good agreement with those obtained from emission $spectra.1$ But the $gJ\pm$ values are in lesser agreement.