Analysis of the CRDS spectrum of 18O3 between 6950 and 7125 cm-1

The absorption spectrum of the O-18(3) isotopologue of ozone was recorded by CW-Cavity Ring Down Spectroscopy in the 6950-7125 cm(-1) region. The typical noise equivalent absorption of the recordings is alpha(min) approximate to 1 x 10(-10) cm(-1). The spectrum is dominated by three very weak bands: 3 nu(1)+5 nu(3) near 7009 cm(-1) and the nu(2)+7 nu(3) and 4 nu(2)+5 nu(3) interacting bands near 7100 cm(-1). In total 260,206 and 133 transitions were assigned for the 3 nu(1)+5 nu(3), nu(2)+7 nu(3) and 4 nu(2)+5 nu(3) bands, respectively. The line positions of the 3 nu(1)+5 nu(3) band were modelled using an effective Hamiltonian (EH) model involving two dark states - (6 0 1) and (2 5 2) - in interaction with the (3 0 5) bright state. The EH model developed for the nu(2)+7 nu(3) and 4 nu(2)+5 nu(3) bands involves only the (0 1 7) and (0 4 5) interacting bright states. Line positions could be reproduced with rms deviations on the order of 0.01 cm(-1) and the dipole transition moment parameters were determined for the three observed bands. The obtained set of parameters and the experimentally determined energy levels were used to generate a list of 984 transitions of the three bands which is provided as Supplementary Material. (C) 2012 Elsevier Ltd. All rights reserved.