Mass-dependent diagonal Born-Oppenheimer corrections (DBOC) to the ab initio electronic ground state potential energy surface for tseveral isotopologues of the ozone molecule are reported for the first time. The comparison with experimental band centers shows a significant improvement of the accuracy with respect to the best Born-Oppenheimer (BO) ab initio calculations reducing the total root-mean-squares (calculated - observed) deviations by about factor of two. For the set of 16O3 vibrations up to five bending and four stretching quanta, the mean (calculated - observed) deviations drop down from 0.7 cm-1 (BO) to about 0.1 cm-1, with the most pronounced improvement seen for bending states and for mixed bend-stretch polyads. In case of bending band centers directly observed under high spectral resolutions, the errors are reduced by more than order of magnitude from observed levels, approaching nearly experimental accuracy. New sets of ab initio vibrational states can be used for improving spectroscopic effective models for analyses of observed high-resolution spectra, particularly in cases of accidental resonances with ,,dark'' states requiring accurate theoretical predictions.
InstitutionInstitute of Chemistry, Eötvös Loránd University
ORCID For Submitting Author0000-0002-7974-6141
Declaration of Conflict of InterestNo conflict of interest