Bowl‐shaped CuB12– Cluster. A viable Global Minimum with Twofold Aromaticity

A low-lying structure is revealed for the CuB12- cluster, which is bowl-shaped. It consists of a triangular CuB2 base and a B-10 rim. Molecular dynamics simulations indicates its structural robustness; at an elevated temperature (600 K), the base rotates reversibly within the B-10 perimeter. Chemical bonding analysis detects 2 sigma- and 3 pi-delocalizeci bonds, suggesting double aromaticity. This is also confirmed by two diatropic and concentric ring currents under an external magnetic field.