The ν5 and 2ν9 Bands of Nitric Acid

Very recently using spectra obtained with a diode-laser technique, a new analysis of the ν5 and 2ν9 interacting bands of nitric acid located at 11 μm has been performed [A. G. Maki and J. S. Wells, J. Mol. Spectrosc.152, 69-79 (1992)]. As compared to this recent analysis, the present work provides: (i) a more extended analysis of the ν5 and 2ν9 bands of HNO3 using a high-resolution Fourier transform spectrum covering the 830-930 cm−1 spectral range, (ii) a different description of the resonances between energy levels of the v5 = 1 and v9 = 2 vibrational states of HNO3 involving both Fermi- and Coriolis-type operators, and (iii) a better description of both the ν5 and 2ν9 bands. In this way, it has been possible to generate an accurate linelist of the P, Q, and R stacks of the ν5 and 2ν9 bands of nitric acid.