High-resolution Fourier transform spectra of HDSe:: The interacting states (v1 v2 v3)/(v1 ± 1 v2 ∓ 2 v3) with 2v1+v2 = 1, 2, 3, and 4

For the first time, high-resolution Fourier transform spectra of HDSe in the region of the three polyads, nu(1)/2 nu(2), nu(1) + nu(2)/3 nu(2), and 2 nu(1)/nu(1) + 2 nu(2)/nu(2) + nu(3), have been recorded and analyzed. Combined with an earlier investigation of the nu(2) band, and including estimates for the unobserved "dark" 4 nu(2) band, these levels were subjected to a "Global Fit," which makes use of relations between parameters within the different polyads. Since there are five isotopic species present in natural (HDSe)-Se-M (M = 82, 80, 78, 77, 76), altogether 34 vibration-rotation bands have been studied in the present contribution. The parameters determined by the Global Fit reproduce upper vibrational-rotational energies of all these bands with accuracies close to experimental precision, (C) 2000 Academic Press.