[Co3@Ge6Sn18]5–: A Giant σ-Aromatic Cluster Analogous to H3+ and Li3+ - Ya-Shan Huang; Hong-Lei Xu; Wen-Juan Tian; Zi-Sheng Li; Sílvia Escayola; Miquel Solà; Alvaro Muñoz-Castro; Zhong-Ming Sun (Journal of the American Chemical Society, 2025)