The 2ν1+ ν2+ 3ν3Band of16O3: Line Positions and Intensities

Abstract

The 2ν1+ ν2+ 3ν3band of ozone, which occurs in the 5700-cm−1region, has been observed for the first time using a Fourier Transform Spectrometer, operating at 0.008 cm−1resolution and with a large pathlength × pressure product (3216 cm × 28.3 Torr). The assignment of rotation–vibration transitions has been done for J up to 38 and Ka up to 11, respectively, after many difficulties due to a Coriolis coupling between (213) and (420) states. In this work we show how this one, which occurs between closed band centers (4 cm−1) but corresponds to ∑iΔvi= 6, strongly perturbs energy levels and leads to a difficulty in assignments. In particular we show the deviations for various types of J and Ka as large as 1 cm−1, with respect to the calculations performed without account of this resonance. The final calculation for the 212 rovibrational states is very satisfactory, as the r.m.s. is 2.5 × 10−3cm−1, near the experimental accuracy, with meaningful spectroscopic Hamiltonian parameters. Rovibrational lines intensities of the 2ν1+ ν2+ 3ν3band were measured, and the value of the transition moment has been recovered. Finally a complete list of line positions and intensities was calculated (with a cut-off of 3 × 10−26cm−1/molecule cm−1) leading to a total band intensity of Sv= 3.118 10−23cm−1/molecule cm−2at 296 K.