MO energy diagrams of the ground state of (a) Th@Au₁₄, (b) [Ac@Au₁₄]^.−, (c) [Pa@Au₁₄]⁺, (d) Pa@Au₁₄, (e) U@Au₁₄. In panel (a), solid red lines denote the major contributions to the respective MOs, while dashed red lines represent the minor contributions. In panels (d) and (e), the red transverse lines represent occupied molecular orbitals. Upper-case and lower-case letters represent the superatomic and atomic orbitals, respectively. Adapted with permission from Ref. [8]. Copyright 2016 Springer.