DIRECT OBSERVATION OF THE GROUND STATE OCTAHEDRAL SPLITTINGS OF $SF_{6}$ USING SATURATION SPECTROSCOPY

Abstract

Owing to the small value of the centrifugal distortion constant $t_{044}$, in the ground vibrational state of $SF_{6}$, hyperfine interactions may mix substantially vibration-rotation states having different point group symmetry types but the same overall parity. As a result, Doppler-generated level crossing appears in the saturation of the $\nu_{3}$ band, halfway between some of the usual Coriolis components. From the intensities and the structure of these cross over peaks, the constant $t_{044}$ can be inferred. We show several examples belonging to the Q branch of $\nu_{3}$, for which a splitting has been resolved.