Vibrational effects in the hydroxyl radical by molecular beam electric resonance spectroscopy

Abstract
The hyperfine Λ-doubling transitions of OH in the 2Π1/2, J=1/2 and 3/2 and in the 2Π3/2, J=3/2 and 5/2 levels of the v=1 and v=2 excited vibrational states have been measured in a molecular beam electric resonance spectrometer. Vibrational effects in the deduced Λ-doubling and hyperfine structure constants have been determined. A comparison is made with ab initio calculations.