Ab initio calculations for Ar2+, He2+ and He3+, of interest for the modelling of ionic rare-gas clusters Original Research Article

Large CI ab initio calculations are performed for Ar2+, He2+ and He3+. For both ionic dimers a complete set of accurate data is determined, including the various electronic states and the transition moments to be used for spectroscopical studies and for modelling larger ionic rare-gas clusters. Spectroscopic constants for Ar2+ are in remarkable agreement with the experimental results. The study for He3+ confirms the failure of the minimal DIM model for helium ions.