The electronic system (2)2Σ+ and (1)2Π of LiCa

High-resolution Fourier transform spectroscopy and Laser-induced fluorescence have been performed on LiCa in the infrared spectral range. We analyse rovibrational transitions of the (2)2Σ+–X(1)2Σ+ system of LiCa and find the (2)2Σ+ state to be perturbed by spin–orbit coupling to the (1)2Π state. We study the coupled system obtaining molecular parameters for the (2)2Σ+ and the (1)2Π state together with effective spin–orbit and spin–rotation coupling constants. The coupled system has also been evaluated by applying a potential function instead of rovibrational molecular parameters for the state (2)2Σ+. An improved analytic potential function of the X(1)2Σ+ state is derived, due to the extension of the observed rotational ladder.