Modeling of HeN+ clusters I. Ab initio and analytical potential energy surfaces for the ground state and two lowest excited states of He3+

Accurate energy ab initio calculations have been performed for three lowest electronic states of He3+ using the internally contracted multireference configuration interaction (icMRCI) method and an augmented correlation-consistent basis set of atomic orbitals. A broad range of He3+ geometries has been considered and the calculated energies have been represented analytically. The present results are thoroughly checked in comparison with data available in the literature.