Knowledge Bank

The visible absorption spectrum of the transition of the iodine molecule has been recorded by means of a Fourier transform spectrometer. The identification of the spectrum of this molecule extending from $14800-20000cm-1$ previously published in an atlas form is now almost complete. In a first step 127 bands were analyzed band by band, and then global fits of the unperturbed lines corresponding to transition from the upper state for $3\le v\prime \le 62$ to the first seven vibrational levels $(0\le v\prime \prime \le 6)$ of the ground state were carried out. The molecular constants obtained are precise enough to reproduce the experimental values of the unperturbated lines with a standard deviation not exceeding $0.001cm-1$ and the identification of almost the 60000 lines of the atlas is possible without ambiguity.