Magic Cluster Anion LaCu₁₂^-: From Superatomic Electronic Structure to Spherical Aromaticity

Area of Science:

• * Materials Science
• * Computational Chemistry
• * Quantum Chemistry

Background:

• * Lanthanum-copper clusters are of interest for their potential material properties.
• * Understanding their structural evolution and stability is crucial for targeted applications.

Purpose of the Study:

• * To systematically investigate the structural evolution and stability of lanthanum-doped copper cluster anions (LaCu_n^-, n = 1-16).
• * To elucidate the electronic factors contributing to the stability of these superatomic clusters.

Main Methods:

• * Unbiased global structure search.
• * Density Functional Theory (DFT) calculations.
• * Mulliken population analysis, Energy Decomposition Analysis (EDA), Adaptive Natural Density Partitioning (AdNDP), and Isochronous Chemical Shielding Surface (ICSS_zz) analysis.

Main Results:

• * Multiple cluster sizes exhibit enhanced energetic stability.
• * LaCu₁₂^- displays a unique compact half-cage geometry.
• * Lanthanum donates electrons to the copper cage, forming a stable 16-electron superatomic closed shell with multicenter delocalized bonds and spherical aromaticity (193 ppm shielding).

Conclusions:

• * The stability of LaCu_n^- clusters arises from a synergistic effect between electrostatic attraction and superatomic electronic shell closure.
• * Findings provide theoretical guidance for designing rare-earth-doped superatomic clusters for functional materials.