A systematic density functional theory investigation has been carried out to explore the possible structures of Sc2C80 at the BMK/6-31G(d) level. The results clearly show that Sc2@C80-Ih, Sc2@C80-D5h, and Sc2C2@C78-C2v can be identified as three isomers of Sc2C80 metallofullerene with the lowest energy. Frontier molecular orbital analysis indicates that the two Sc2@C80 isomers have a charge state as (Sc3+)2@C806-and the Sc2C2@C78 has a charge state of (Sc3+)2C22-@C784-. Moreover, the metal-cage covalent interactions have been studied to reveal the dynamics of endohedral moiety. The vertical electron affinity, vertical ionization potential, infrared spectra and 13C nuclear magnetic resonance spectra have been also computed to further disclose the molecular structures and properties.National Natural Science Foundation of China (NSFC) [20821003, 91027108, 20702053, 20973137]; NSAF [11076027]; Chinese Academy of Sciences; China Postdoctoral Science Foundation [20100480027]; K. C. Wong Education Foundation, Hong Kon