Ab initio potential curves for the , and states of

We report ab initio calculations of the X 2 Σ u + , A 2 Π u and B 2 Σ g + states of the Ca 2 + dimer. All electron CAS + MRCI calculations are performed for the X 2 Σ u + and B 2 Σ g + states, while valence CAS + MRCI calculations using an effective core potential are used to describe the A 2 Π u state. A double well is found in the B 2 Σ g + state. Spectroscopic constants, vibrational levels, transition moments and radiative lifetimes are calculated for the most abundant isotope of calcium ( 40 Ca ). The static dipole and quadrupole polarizabilities, and the leading order van der Waals coefficients are also calculated for all three states.