Topological efficiency of C66 fullerene

► First theoretical explanation of peculiar topological stability of C66-C2v molecule detected in Sc2@C66 endoclusters. ► Elegant and very fast computational method to screen relevant isomers to be investigates with time-consuming ab initio methods. ► Topological efficiency invariant helps in understanding of formation mechanisms of complex structures, like large fullerenes or graphene lattices.