High resolution FTIR study of ³⁴S¹⁶O₂: The bands 2_ν3, 2_ν1+_ν2 and 2_ν1+_ν2-_ν2

The high resolution infrared spectrum of the ³⁴S¹⁶O₂ molecule was recorded in the region of 2600-2810 cm^-1 where the strong 2_ν3 band is located. About 2500 transitions with maximum values of quantum numbers ^Jmax.=76 and Kamax.=26 were assigned to the 2_ν3 band. The very weak 2_ν1+_ν2 band was recorded and analyzed for the first time. This gave us the possibility to find and analyze, for the first time, the hot band 2_ν1+_ν2-_ν2, which is located in the 2200-2380 cm^-1 region and totally covered by the strong 2_ν1 band. In general, about 1370 transitions were assigned to the bands 2_ν1+_ν2 and 2_ν1+_ν2-_ν2, and 302 ro-vibrational energies of the (2 1 0) state were determined. Ro-vibrational energies obtained from experimental data for both the (0 0 2), and (2 1 0) vibrational states were used in the weighted list square fit of the parameters of the effective Hamiltonian, which takes into account additional interactions with the (1 3 0) and (0 5 0) vibrational states. The set of parameters obtained from the fit reproduces the initial experimental data with accuracies close to experimental uncertainties.