RELATIVISTIC CALCULATIONS OF EXCITED-STATES OF MOLECULAR-IODINE

An ab initio relativistic atomic pseudopotential method is used for the calculation of the 23 valence excited states of the 12 molecule which dissociate into the P-2(J)+P-2(J') (J, J' = 3/2, 1/2) atomic states. The vertical transition energies are in very good agreement with experimental results, and the deficiency of the dissociation energy is discussed. The potential energy curves are given without and with spin-orbit coupling, and a semi-empirical improvement is proposed. In this way, we obtain for the first time very reliable potential energy curves for these excited states. The quality of these curves is tested by a careful comparison with all the available experimental data.