Neither too Classic nor too exotic: One‐electron Na·B Bond in NaBH3‐ Cluster

It is here reported that the NaBH3- cluster exhibits a Na⋅B one-electron bond, a well-established type of electron-deficient bonding in the literature. The topological analysis of the electron localization function, at the correlated level, reveals that Na- , when approaching the bonding distance, fairly distributes its valence electron pair between two lobes. One of these electrons is used to bond with BH3 , which participates through its boron empty p-orbital. Furthermore, the bonding situation of LiBH3- , KBH3- , MgBH3 , and CaBH3 global minima structures are similar to that of NaBH3- , extending the family of these new one-electron bond systems with biradicaloid character.