Infraredndash;microwave double resonance spectroscopy of the SiF4ngr;3fundamental using a tunable diode laser

摘要

Pure rotational spectrum of silicon tetrafluoride SiF4is investigated in the ngr;3vibrational state by infraredndash;microwave double resonance. Frequency tunable semiconductor diode lasers are used as an infrared pumping radiation source. 106 radiofrequency transitions among the tetrahedral fine structure splittings and 60 microwave transitions among the various Coriolis sublevels are measured with an accuracy of a few tens of kilohertz. Seven scalar and four tensor constants of the excited state are determined accurately. A part of the badly congested infraredQhyphen;branch spectrum is analyzed on the basis of assignment by double resonance. Three groundhyphen;state constantsB0,D0, andD044are determined.