ab initio R-matrix and MQDT investigation of low-lying Rydberg states of the HeH+ molecular ion I. Bouhali, S. Bezzaouia, M. Telmini and Ch. Jungen EPJ Web of Conferences, 84 (2015) 04004 Published online: 29 January 2015 DOI: 10.1051/epjconf/20158404004