K-Type Doubling Lines of H₂CO and HCOOH in the HF Region

Abstract

Fourteen lines of K-type doubling in H₂CO and HCOOH were observed in the frequency range of 2 to 33 MHz by a beam maser spectrometer. The observed frequencies are compared with the values calculated from the molecular constants which have been obtained in the microwave region. The agreement between the observed and the calculated transition frequencies of H₂CO is good, though the fractional deviations for the lines in the HF region are about an order of magnitude greater than those in the microwave region. In the case of HCOOH the agreement is rather poor and some refinement in the molecular constants seems to be necessary.