High-resolution spectroscopic study of H2 80 Se in the ν(stretch) = 5 and 6 local-mode pairs states

Abstract

High-resolution spectra of the H2 80Se molecule (50±,0), A1/B2 and (60±,0), A1/B2 (local mode pairs) stretching states were recorded using a Fourier transform spectrometry technique and also a Ti: sapphire laser photo-acoustic spectrometer with resonance cavity and multi-pass cell. The vibrational wavefunction, stretching band origins, rotational constants and Coriolis coefficients of H2 80Se molecule ν = 5 and 6 local-mode pairs were calculated by using the NMDD (normal mode with Darling—Dennison resonance included) model. These parameters were used to predict the upper state energy levels, which were used as the bases of ground state combination differences for assigning the vibration—rotational transitions of H2 80Se molecule ν = 5 and 6 local-mode pairs states. Several striking local-mode limit effects and the formation of four-fold ro-vibrational energy clusters were observed and discussed.