HIGH-RESOLUTION INFRARED-EMISSION SPECTRA OF GAH AND GAD

The high resolution infrared emission spectra of gallium hydride and gallium deuteride have been recorded with a Fourier transform spectrometer. There were 1045 lines observed including those from the v = 1 --> 0 to v = 7 --> 6 bands for the (GaD)-Ga-69 and (GaD)-Ga-71 species and v = 1 --> 0 to v = 4 --> 3 bands for the (GaH)-Ga-69 and (GaH)-Ga-71 species. Dunham Y(ij)'s for each isotopomer were obtained by fitting the data set of each isotopomer separately to the Dunham energy levels of the X1SIGMA+ electronic ground state. The mass-reduced Dunham U(ij)'s were determined using two independent methods. In the first fit the U(ij)'s constants were determined by the traditional method where all the constants were treated as adjustable parameters and determined statistically. In the second fit the U(ij)'s which satisfied the condition j < 2 were treated as adjustable parameters and the remaining constants were fixed by constraints imposed by the Dunham model. In order to predict the positions of transitions with v's and J's much higher than those observed the entire data set was fit directly to the eigenvalues of the Schrodinger equation containing a parameterized internuclear potential energy function.