Spectroscopic study of the E(4)1sigma+ state in NaLi.

Polarization labelling spectroscopy is applied to study the excited E1sigma+ state of NaLi in the energy range 26,500-28,000 cm(-1) above the bottom of the ground state. The potential curve of the E state is constructed using the Inverted Perturbation Approach method. The values of Te, omega(e) and Re are found to be 26,474.82(4), 180.3(2) cm(-1) and 3.343(1) A, respectively.