VUV-VIS FT spectroscopy of the rare CO isotopologue of carbon monoxide: Analysis of the AΠ(v = 1) multiply-perturbed level.

Ro-vibronic spectra of the CO carbon monoxide isotopologue were obtained with (i) emission spectroscopy in the visible region using a Bruker IFS 125HR spectrometer (University of Rzeszów) and (ii) vacuum-ultraviolet absorption spectroscopy using the wave-front-division spectrometer on the DESIRS beamline of the SOLEIL synchrotron. A deperturbation analysis of the CO AΠ(v = 1) level was conducted from 598 observed transitions from the BΣ - AΠ(0, 1), CΣ - AΠ(0, 1), AΠ - XΣ(1, 0), BΣ - XΣ(0, 0), CΣ - XΣ(0, 0), IΣ - XΣ(2, 0) bands and five further nominally forbidden bands. An effective Hamiltonian and term-value fitting analysis was implemented.