Ti@Ag14, as a Double-Magic Cluster. Superatomic and Spherical Aromatic Characteristics in an Oblate 18-ce Cage

Abstract

The quest for persistent silver clusters, enables targeting candidates for designing novel atomically precise structures. Here, we evaluate the Ti@Ag₁₄ cluster as a highly symmetric oblate D_6d structure, featuring an endohedral Ti atom. The Ti-Ag₁₄ bonding interaction is sizable, which involves a balance between both stabilizing and steric repulsion contributions. The resulting cluster features a 1S²1P⁶1D¹⁰ superatomic shell structure which infers spherical aromatic characteristics, as confirmed by magnetic and electron delocalization analyses. Charge distribution over the van der Walls surface, unravel several localized σ-hole electron deficient regions at the cluster vertices, providing multiple reactive Lewis acidic sites. These features suggest Ti@Ag₁₄ as a double-magic cluster, as a novel stable spherical aromatic superatom with particular electronic and cluster surface properties.