Potential energy curves for the triplet states of the ionic excimer Ar22+are computed in an all-electron treatment employing multireference configuration interaction (MRD-CI) calculations. The six states3Σ+u(2),3Πg,3Πu,3Δuand3Σ-gdissociating into Ar+(2Pu) + Ar+(2Pu) are confirmed to be repulsive, while the four triplets3Πg,3Πu,3Σ-gand3Σ-udissociating into Ar2+(3Pg) + Ar(1Sg) are computed to be weakly bound possessing equilibrium distances between 5·6 and 6·0 bohr and dissociation energies in the range of 2450–3180 cm-1. According to the calculation, the strongest bound-free emission occurs fromv′ = 0 of the 23Πgstate at 182 nm followed by the 23Πu-3Πgtransition at 181·8 nm and de-excitation from the3Σ-ustate around 168 nm; it is unambiguously assigned to the first maximum measured around 183 nm in the third continuum of the argon excimer spectrum. The calculated radiative lifetime of 6 ns (compared with the measured value of 5 ns) also supports this assignment.