Rotational analysis of the à ngström system (B1Σ+-A1Î ) in the rare 13C17O isotopologue

► First emission spectroscopy of the Ångström (B-A) system of rare 13C17O isotopic molecule. ► Rotational analysis of the 0-1 and 0-2 bands. ► Detailed analysis of the multistate perturbations in the A state. ► So far unknown molecular constants of the B and A states in the 13C17O.