Missing Recipe in the Na‐B Bond in NaBH ₃ ^– Cluster

Abstract The multifaceted little Na−B bond in NaBH 3 ‐ cluster has been the subject of many recent studies. Many proposals have been put forward for the complete understanding of the chemical bonding in NaBH 3 ‐ cluster. However, none of the studies provided a complete picture. Herein, the missing recipe of the chemical bonding in NaBH 3 ‐ cluster has been identified which completes the description. Our calculations reveal that the chemical bonding in NaBH 3 ‐ cluster is more multifaceted than ever thought. Our finding suggests that the NaBH 3 ‐ cluster features a Na−B one electron bond which is assisted by three 3‐centre‐2‐electron Na‐B−H bond. Detailed topological analyses of electron density and electron localization function at the correlated level reveal such a bonding situation. This missing 3‐centre‐2‐electron Na‐B−H bond completes the description of chemical bonding in NaBH 3 ‐ cluster which is at‐per with the well established bonding scenario for electron deficient compounds. Similar bonding scenario is observed in KBH 3 − , CuBH 3 ‐ and AuBH 3 − clusters, further lending support to the complete picture of bonding.