MARVEL analysis of high-resolution rovibrational spectra of ¹⁶O¹³C¹⁷O and ¹⁷O¹²C¹⁷O

Spectroscopic networks (SN) are assembled for the carbon dioxide (CO2) isotopologues 16O13C17O/17O12C17O (637/727, according to a well-established shorthand notation adopted in this study), based on line-centre measurements listed in 19/16 literature studies. For the isotopologues 637/727, the SNs contain 5053(3099)/10,256(6657) measured(unique) transitions, determining 18/38 vibrational band origins, defined as the lowest-energy state for a set of vibrational quantum numbers. The transitions collected span the wavenumber regions 617–8061/582–12,570 cm−1 for 637/727. These SNs determine 1960/3278 empirical rovibrational energy levels for 637/727, extracted with the help of the MARVEL (Measured Active Rotational-Vibrational Energy Levels) protocol and code. The energy levels of 637/727 span the regions 0–9210/0–13,199 <i>hc</i> cm−1 and the polyad numbers <i>P</i> from 0–12 for 637 and from 0–11 and 17 for 727 (where P=2v1+v2+3v3, and the quantum numbers v1, v2, and v3 represent the symmetric stretch, bend, and antisymmetric stretch motions). Comparison of the empirical rovibrational energy levels determined in this study with their counterparts in two published databases, CDSD-296 and Ames-2021, shows very good overall agreement.