Nb11O15−. As a persistent spherical antiaromatic cluster

The formation of persistent molecular units for further materials requires acquiring insights into the rich versatility of available species. The Nb₁₁O₁₅⁻ cluster exhibits a sizable frontier orbital gap with particular stability. Its electronic structure denotes a partially filled 1F superatomic shell, not fulfilling the 2(N + 1)² Hirsh rule for spherical aromatic species. Our results unravel a spherical antiaromatic behavior, which is scarce in literature. Furthermore, to gain a fundamental understanding of the accounted results, both diamagnetic and paramagnetic contributions to the overall magnetic behavior are discussed. Thus, Nb₁₁O₁₅⁻ is an interesting oxo-bridged cluster, featuring spherical antiaromaticity as a stable cluster unit.