By using high-level ab initio calculations, we investigated series of diatomic radical cations designed to create a localized electronic transition suitable for optical cycling. The results demonstrate that the localized electronic excitation picture exploited in OCCs in neutral molecules to some extent holds for isoelectronic cations formed by transitionmetal atoms. This result applies to molecular cations that either contain a transition metal atom or have multiple bonds, which is different from the behavior of other cations 1 .