Determination of the C(3)1Σ+ state potential energy curve in KCs molecule based on polarisation labelling spectroscopy data

The C(3)1Σ+ state of KCsmolecule was studied experimentally employing the polarisation labelling spectroscopy (PLS) technique. The experiment extended the prior knowledge of the state adding more than 40 vibrational levels to the previously existing data. A pointwise potential energy curve was constructed for the investigated state with the inverted perturbation approach (IPA) method, basing on experimentally determined energies of over 1300 rovibrational levels.