Fig. 1: Structure and schematic illustration.

a DFT-optimized molecular structure of Y2@C79N at the level of B3LYP/6-31 G* ~ LANL2DZ for Y. (Nitrogen atom, carbon atoms and yttrium atoms are respectively colored in indigo, blue, and rose-red spheres.). b Calculated spin density distributions (orange) of Y2@C79N. c Schematic of the interaction between the N-substituted region in C79N cage and benzene ring. d Schematic of the orientation of Y2@C79N in crystalline aromatic materials.