Hammami H, Yazidi O, Ben El Hadj Rhouma M, Al Mogren M M, Hochlaf M
Université Paris-Est, Laboratoire Modélisation et Simulation Multi Echelle, MSME UMR 8208 CNRS, 5 bd Descartes, 77454 Marne-la-Vallée, France.
Laboratoire de Spectroscopie Atomique Moléculaire et Applications, Département de Physique, Faculté des Sciences de Tunis, Université de Tunis-El Manar, Le Belvédère, 1060 Tunis, Tunisie.
J Chem Phys. 2014 Jul 7;141(1):014302. doi: 10.1063/1.4884960.
Using ab initio methodology, we studied the IO(q+) (q = 2, 3, 4) multi-charged ions. Benchmark computations on the IO(X(2)Π) neutral species allow validate the current procedure. For IO(2+), several potential wells were found on the ground and the electronic excited states potentials with potential barriers with respect to dissociation, where this dication can exist in the gas phase as long-lived metastable molecules. We confirm hence the recent observation of the dication by mass spectrometry. Moreover, we predict the existence of the metastable IO(3+) trication, where a shallow potential well along the IO internuclear distance is computed. This potential well supports more than 10 vibrational levels. The IO(3+) excited states are repulsive in nature, as well as the computed potentials for the IO(4+) tetracation. For the bound states, we give a set of spectroscopic parameters including excitation transition energies, equilibrium distances, harmonic and anharmonic vibrational terms, and rotational constants. At the MRCI + Q/aug-cc-pV5Z(-PP) level, the adiabatic double and triple ionization energies of IO are computed to be ~28.1 eV and ~55.0 eV, respectively.
