Joint ro-vibrational analysis of the HDS high resolution infrared data

High resolution Fourier transform spectra of the HDS molecule were recorded and analyzed for the first time in the region of the bands ν₁ + 2ν₂ (3938.6 cm⁻¹), ν₁ + ν₃ (4522.6 cm⁻¹), 2ν₂ + ν₃ (4638.8 cm⁻¹), 2ν₁ + ν₂ (4767.7 cm⁻¹), ν₁ + ν₂ + ν₃ (5525.2 cm⁻¹), 3ν₁ (5560.6 cm⁻¹), ν₁ + 2ν₃ (7047.2 cm⁻¹), and 2ν₂ + 2ν₃ (7123.9 cm⁻¹). The ro-vibrational energies of the upper vibrational states of these bands together with the ro-vibrational energies of 12 other bands already studied at high resolution were used as inputs in a Global Fit analysis firstly described in O.N. Ulenikov, G.A. Onopenko, H. Lin, J.-H. Zhang, Z.-Y. Zhou, Q.-S. Zhu, R.N. Tolchenov, J. Mol. Spectrosc. 189 (1998) 29-39]. In this case, the resonance interactions between the states (v₁v₂v₃) and (v₁ ± 2 v₂ ? 1 v₃ ? 1) were taken into account. The resulting set of 143 parameters reproduces all the experimental data (2984 vibration-rotation energies of 20 vibrational states which correspond to about 9700 ro-vibrational transitions with J^max = 23) with accuracies comparable with the experimental uncertainties.