Analysis of highly excited 'hot' bands in the SO2 molecule: v(2)+3v(3)-v(2) and 2v(1)+v(2)+v(3)-v(2)
Résumé
We set up a variational procedure of assignments of transitions and we applied it to the analysis very weak 'hot' bands, v(2) + 3v(3) - v(2) and 2v(1) + v(2) + v(3) - v(2), of the SO2 molecule. As the first step of the study, the 'cold' bands, 3v(3) and 2v(1) + v(3), are re-analysed and transitions belonging to those bands are assigned up to the values of quantum numbers J(max.) = 60, K-a(max.) = 19, and J(max.) = 69, K-a(max.) = 20 for the bands 3v(3) and 2v(1) + v(3), respectively. After 'cleaning' the experimental spectrum from transitions belonging to the 3v(3) and 2v(1) + v(3) bands, a variational procedure was used that allowed us to assign 230 and 115 transitions with the values of quantum numbers J(max.) = 35, K-a(max.) = 10, and J(max.) = 26, K-a(max.) = 11 for the bands v(2) + 3v(3) - v(2) and 2v(1) + v(2) + v(3) - v(2), respectively. The sets of spectroscopic parameters obtained by fitting the assigned experimental transitions reproduce the initial experimental data with an accuracy close to experimental uncertainties.