Timur Grigorev, Yuhang Dai, Max Potter, Xiaoyu Xiang, Keyu Zhang, J. Tennyson
Abstract Carbon monoxide is thought to be the second most abundant molecule in the Universe. This makes observation of both its parent isotopologue ( 12 C 16 O) and its stable isotopologues, 13 C 16 O, 12 C 18 O, 12 C 17 O, 13 C 18 O, and 13 C 17 O, important in variety of objects. Here the Measured Active Rotational-Vibrational Energy Levels algorithm is used to determine precise rotational–vibrational energy levels for the five minor isotopologues of carbon monoxide in their electronic ground state. A review of 27 literature sources yields 3716, 1454, 89, 728, and 57 validated transitions for 13 C 16 O, 12 C 18 O, 12 C 17 O, 13 C 18 O, and 13 C 17 O, respectively, giving 863, 499, 33, 345, and 45 empirically determined, rotation–vibration energy levels, respectively.