Extended Data Fig. 1: Molecular structures of Y₂Ni@C_3v(8)-C₈₂ and Y₂Ni@C_s(6)-C₈₂.

a,b Thermal ellipsoid plots of Y₂Ni@C_3v(8)-C₈₂·Ni^IIOEP·C₆H₆ (a) and Y₂Ni@C_s(6)-C₈₂·2(DPC)·2C₇H₈ (b); only the major sites of Y and Ni are shown, and the solvent molecules are omitted for clarity. c,d Front views of Y₂Ni@C_3v(8)-C₈₂ (c) and Y₂Ni@C_s(6)-C₈₂ (d). e,f Close-up views of the Y₂Ni clusters and the adjacent cage fragments in Y₂Ni@C_3v(8)-C₈₂ (e) and Y₂Ni@C_s(6)-C₈₂ (f), annotated with experimental Y–Ni bond lengths, Y-to-ring centroid and Y-to-bond centroid distances, and Y–Ni–Y angles. Y is represented by green, Ni by yellow, C by gray and N by cyan.