CHARACTERIZATION OF HOMONUCLEAR DIATOMIC IONS BY SEMIEMPIRICAL MORSE POTENTIAL-ENERGY CURVES .2. THE RARE-GAS POSITIVE-IONS

Morse potential energy curves for the lowest six states of the rare ga s positive ion dimers have been calculated on the basis of experimenta l data. For the ground states, there are sufficient measured data to d efine the curves completely. For the excited states of all the positiv e ion dimers except neon, there an sufficient measured data to define the curves. To obtain these curves, new assignments of vibrational pro gressions in high-resolution photoelectron spectra previously publishe d are made and the vertical ionization potentials obtained. The vertic al ionization potentials are used to determine the internuclear distan ces, The ground state ionic and neutral radii for Ne to Xe are 63, 93, 105, and 123 pm and 112, 152, 168, and 194 pm, respectively. ''Virtua l'' covalent radii for Ne to Xe are 69, 98, 111, and 126 pm. The curve s are consistent with the van der Waals radii of Ne to Xe, which are 1 54, 185, 200, and 218 pm. From The correlation between the Morse param eters of the isoelectronic ions and the new data for the rare gas posi tive ions, improved Morse potential energy curves for both the halogen negative ion dimers and the rare gas positive ion dimers are obtained .