Measurement of the LiD (<i>A</i>–<i>X</i>) transition moment from laser-excited fluorescence and test of the <i>R</i>-centroid approximation

Abstract

Improved Dunham coefficients of the X 1Σ+ and A 1Σ+ states of LiD were derived, based on the observation of vibrational levels up to v″ = 26, corresponding to 96% of the ground state dissociation energy. From accurate intensity measurements over long fluorescence progressions, the electronic transition moment M was obtained as a function of the internuclear distance R. The dependence M(R) has an unusual S shape. The R-centroid method was found to be valid even in this case.