In this set of cations we again inspect the transition between the ground and the first excited states. The increased energy gaps in Ti and V relative to Sc improve the radiative lifetimes. The heavy atoms Zr and Nb also have stronger SOCs, which increases transition dipole moment, but an improvement in the radiative lifetime is achieved only for Nb as in the Zr cations the 1 2 ∆ and 1 2 Σ states become nearly degenerate. The small improvement in the radiative lifetime of the 1 2 Σ → 1 2 ∆ 3/2 transition in multiply bonded cations is accompanied by a large improvement in the diagonality of the corresponding FCFs, Sec. S3 in the SI, making this transition very a promising OCC. The best candidate in this group is the NbN + cation, with FCFs summarized in Table and the radiative lifetime τ = 650 µs.