AbstractThe geometries and electronic structures of molecular ions featuring He atoms complexed to actinide cations are explored computationally using density functional and coupled cluster theories. A new record coordination number is established, as AcHe173+, ThHe174+, and PaHe174+are all found to be true geometric minima, with the He atoms clearly located in the first shell around the actinide. Analysis of AcHen3+(n=1–17) using the quantum theory of atoms in molecules (QTAIM) confirms these systems as having closed shell, charge‐induced dipole bonding. Excellent correlations (R2>0.95) are found between QTAIM metrics (bond critical point electron densities and delocalization indices) and the average Ac−He distances, and also with the incremental He binding energies.