e Q q measurements in the X, 1g, O+g and B state of I2: A test of the electronic molecular eigenfunctions

The laser induced fluorescence spectra of I2 recorded with a high resolution Fourier Transform Spectrometer (LIF–FTS) enables us to measure the hyperfine parameters eQq in three states of I2; the X state and the recently discovered 1g and O+g states. For each state eQq is obtained in various vibrational levels and especially in the X state, we obtain the complete variation curve of eQq as a function of the vibrational energy. All these results and some other ones available in the literature are interpreted using LCAO eigenfunctions for short internuclear distance and separated atom basis set near the dissociation limit. The agreement with the experimental results is very good and it is possible to observe the transition between the two basis sets.