Ab initio electronic structure investigation of protonated mixed rare gas dimers [NeHHe]+, [ArHHe]+ and [ArHNe]+

► Benchmark calculations of electronic structures of protonated rare gas clusters, [NeHHe]+, [ArHHe]+, and [ArHNe]+ are presented. ► In addition to the most stable structures (with hydrogen in the middle), two additional local minima are located. ► Harmonic frequencies of all the structures are reported.