Ab initio potential curves for the X $^2\Sigma_u^+$, A $^2\Pi_u$ and B $^2\Sigma_g^+$ states of Ca$_{2}^+$

We report ab initio calculations of the X2Σu+, A2Πu and B2Σg+ states of the Ca2+ dimer. All electron CAS+MRCI calculations are performed for the X2Σu+ and B2Σg+ states, while valence CAS+MRCI calculations using an effective core potential are used to describe the A2Πu state. A double well is found in the B2Σg+state. Spectroscopic constants, vibrational levels, transition moments and radiative lifetimes are calculated for the most abundant isotope of calcium (40Ca). The static dipole and quadrupole polarizabilities, and the leading order van der Waals coefficients are also calculated for all three states.