Core-excited molecular states: theoretical and experimental investigation of the Li2molecule

The excitation and decay of core-excited molecular lithium has been investigated by experimental and theoretical methods. The associated far-UV photoabsorption spectrum, which was observed with partly resolved vibrational structure, was interpreted on the basis of configuration-interaction (CI) calculations. In addition, the autoionisation of these states was investigated by ejected-electron spectroscopy and explained through the use of a stationary Born-Oppenheimer model. A theoretical determination of the related potential curves and the 1s ionisation potential is presented along with a discussion of the electronic structure of the core-excited states.