Ab initio approaches for [formula omitted] and [formula omitted] ions towards modeling of the [formula omitted] ion in cold helium plasma

Abstract

As a first step towards realistic modeling of transport properties of the N2+ ion in helium gas, detailed investigations of the electronic structure of the ion as well as the N2+/He collision complex have been performed with the main focus on computational efficiency and accuracy. A broad range of correlation consistent basis sets and representative orbital spaces have been considered for both computationally cheap multi-configuration self-consistent field (MCSCF) methods and benchmark multi-reference configuration interaction (MRCI) approaches. It has been found that the computationally advantageous MCSCF approach, even if combined with basis sets of moderate sizes, leads to an acceptable accuracy and is thus suitable for direct dynamics simulations of N2+/He collisions to be addressed in subsequent works.