The 2ν2Band of Water: Analysis of New FTS Measurements and High-KaTransitions and Energy Levels☆

Abstract The spectrum of water has been recorded at high resolution in the range 2500–4560 cm −1 . The spectrum was recorded at room temperature with a Fourier transform spectrometer using fully evacuated transfer optics and a White-type multi-reflection cell which made large pressure × pathlength products possible. Among 3385 lines assigned to transitions to the first triad of interacting states of H 2 16 O (bands 2ν 2 , ν 1 , and ν 3 ), 940 vibration–rotation transitions have been assigned to the 2ν 2 band, approximately 300 of them for the first time. According to our assignments some of these transitions, especially high- K a transitions, show significant deviations from data available in various compilations and in previously published reports. Improved values of vibration–rotation energies of the (020) state up to J = 17 and K a = 11 were determined. The anomalously strong centrifugal distortion of the (020) rotational levels and their resonance interactions with the (100) and (001) levels have been accounted for using the generating function model (1992, Vl. G. Tyuterev, J. Mol. Spectrosc. 151, 97–130; 1995, Vl. G. Tyuterev, V. I. Starikov, S. A. Tashkun, and S. N. Mikhailenko, J. Mol. Spectrosc. 170, 38–58), which allows a good agreement with observed data. The RMS standard deviation of the least-squares fit of vibration–rotational levels of the (020) state was 2.2 × 10 −3 cm −1 .