An atlas of endohedral Sc₂S cluster fullerenes

Structural identification is a difficult task in the study of metallofullerenes, but understanding of the mechanism of formation of these structures is a pre-requisite for new high-yield synthetic methods. Here, systematic density functional theory calculations demonstrate that metal sulfide fullerenes Sc₂S@C_n have similar cage geometries from C₇₀ to C₈₄ and form a close-knit family of structures related by Endo-Kroto insertion/extrusion of C₂ units and Stone-Wales isomerization transformations. The stabilities predicted for favoured isomers by DFT calculations are in good agreement with available experimental observations, have implications for the formation of metallofullerenes, and will aid structural identification from within the combinatorially vast pool of conceivable isomers.