A determination of the spinndash;rotation parameters for NO2in theXtilde;thinsp;2A1state by microwavendash;optical double resonance

摘要

Magnetic dipole transitions between the spin components of rotational levels of NO2in its ground state have been observed by the technique of microwavendash;optical double resonance. Fluorescence induced by an argon ion laser was used to monitor the process. Observations were made in the range 4 to 12 GHz and provide information on levels with a wide spread ofNandKavalues. The results have been used in conjunction with the known electric dipole transition frequencies and some recent data from radio frequencyndash;infrared double resonance to determine the rotational and spinndash;rotational parameters for the molecule in its ground state. It has proved possible to determine all the three quadratic and six quartic parameters in the spinndash;rotational Hamiltonian. The improvement in knowledge of the spinndash;rotation intervals allow a refinement of the Zeeman parameters for NO2by refitting the data from the EPR and LMR spectra. The results are in good agreement with the relationshipsgSaa=gSminus;eaa/2Baa, etc.