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 \textit{ab initio} calculations of the X $^2 \Sigma_{u}^+$, A $^2\Pi_u$ and B $^2 \Sigma_{g}^+$ states of the Ca$_{2}^+$ dimer. All electron CAS+MRCI calculations are performed for the X $^2 \Sigma_{u}^+$ and B $^2 \Sigma_{g}^+$ states, while valence CAS+MRCI calculations using an effective core potential are used to describe the A $^2\Pi_u$ state. A double well is found in the B $^2 \Sigma_{g}^+$ 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. 
Sandipan Banerjee, John A. Montgomery Jr., Jason N. Byrd, H. Harvey   Michels, Robin C\^ot\'e
physics.chem-ph physics.atom-ph physics.comp-ph