Be4B12+: A Covalently Bonded Archimedean Beryllo‐Borospherene.

A new class of beryllium‐boron clusters, beryllo‐borospherene, is described herein theoretically. When beryllium is gradually added to the B12 motif, it undergoes drastic structural modifications. The global minimum of the Be4B12+ cluster is an Archimedean beryllo‐borospherene in a 2A1 electronic ground state, composed of four boron triangles linked at each corner, resulting in a truncated tetrahedron with four B6 rings capped with four beryllium atoms. Beryllium forms strong bonding with the boron clusters through strong electrostatic and covalent interactions. For instance, the bonding between a beryllium atom and Be3B12 unit is best described as a Be+ fragment in a 2P excited state forming a strong and polarized electron‐sharing bond with Be3B12, followed by several dative interactions by employing its vacant s, p, and very high‐lying d orbitals. Counterintuitively, for an s‐block element, the p orbitals of beryllium are the most crucial atomic orbitals for bonding rather than s orbitals. [ABSTRACT FROM AUTHOR]