High resolution infrared emission spectra of AlH and AlD

High resolution infrared emission spectra of aluminum monohydride and monodeuteride have been recorded. Gaseous AlH and AlD were generated by reacting molten aluminum metal with hydrogen and deuterium gas. Approximately 265 AlH lines with v=1→0 to v=5→4 and 470 AlD lines with v=1→0 to v=7→6 are reported. Dunham Yij constants were obtained by fitting the data of each isotopomer separately to the Dunham energy level expression while mass-reduced Dunham Uij constants were obtained from a combined fit of all isotopomer data. A second set of Dunham Uij constants was obtained from a fit where Uij’s with j<2 were treated as adjustable parameters and all remaining Uij’s fixed to values that satisfy the constraints imposed by the Dunham model. Finally, an effective Born–Oppenheimer potential was determined by fitting all the data directly to the eigenvalues of the radial Schrödinger equation containing a parametrized potential function.