THE INFRARED-EMISSION SPECTRA OF LIF AND HF

The high resolution infrared spectrum of LiF has been measured in emission with the McMath Fourier transform interferometer at Kitt Peak. A total of 800 lines with v = 1 --> 0 to v = 8 --> 7 of the main isotopomer, 7LiF, and 250 lines with v = 1 --> 0 to v = 3 --> 2 of the minor isotopomer, 6LiF, were observed. These ro-vibrational transitions and the pure rotational transitions from the literature were fit to a set of Dunham coefficients Y(ij) and a set of mass-reduced Dunham coefficients U(ij). The same spectrum shows 13 pure rotational emission transitions of HF in the vibrational ground state with J = 13 --> 12 to J = 25 --> 24. These transitions were used to determine an improved set of rotational constants for HF.