Three new bands of 18O16O18O by CW-CRDS between 6340 and 6800 cm−1

- Cavity Ring Down Spectroscopy of 18O16O18O between 6340 and 6800 cm−1.
- 976 Transitions assigned to three vibrational bands.
- Highest vibrational bands observed so far for the 18O16O18O isotopologue.
- Effective operator modelling of the spectra.
- Good agreement with ab initio values for the band centres and rotational constants.

Three very weak bands of the 18O16O18O isotopologue of ozone have been detected by high sensitivity CW-Cavity Ring Down Spectroscopy between 6340 and 6800 cm−1. They are vibrationally assigned as 2ν1+5ν3, ν1+4ν2+3ν3 and 3ν2+5ν3 and correspond to the highest frequency bands of this isotopologue detected so far. A total of 464, 318 and 194 transitions were rovibrationally assigned, respectively. The good agreement with theoretical values achieved for the derived band centres and rotational constants confirms the accuracy of the potential energy surface recently obtained via extensive ab initio calculations. A set of line intensities was measured and fitted to derive the first transition moment parameter of the three bands. The determined sets of effective Hamiltonian parameter and transition moment operators, as well as the experimental energy levels, were used to generate a complete list of 1526 transitions, provided as Supplementary materials. The calculated line-list allows generating a synthetic spectrum which reproduces satisfactorily the experimental spectrum.