On the ground vibrational level of the A3Π1ustate of the I2molecule

The study of the iodine absorption spectrum by means of Fourier spectroscopy in the near infrared between 7000 and 12500 cm -1 shows that the vibrational numbering of the A 3 Pi 1u state proposed recently by Ashby (1979) has to be increased by two units. The separation between the two states X 1 Sigma g + and A 3 Pi 1u is found to be equal to 10846.35 cm -1 and the dissociation energies D 0 and D e of the A state are equal to 1593.75 and 1639.77 cm -1 respectively. Franck-Condon factors (FCF) have been calculated and the computed relative intensities are consistent with the observed ones.