A study of the low-lying states of CaAr+ and CaKr+

The spectroscopic constants of the ground 2Σ+ states of CaAr+ and CaKr+ are determined using high quality ab initio methods. The computed binding energies are 789 and 1252 cm−1, respectively, in good agreement with the experimental determination of Pullins, Scurlock, Reddic and Duncan (J. Chem. Phys. 104 (1996) 7518). The much smaller CaKr+ binding energy determined by Buthelezi, Bellert, Lewis and Brucat (Chem. Phys. Lett. 246 (1995) 145) is shown to be due to deficiencies in the method used to approximate the binding energy of the excited state.