Structural study of endohedral dimetallofullerenes Sc-2@C-84 and Sc-2@C-74

Ab initio molecular orbital and density functional calculations are carried out to predict the structures of the Sc-2@C-84 isomers. It is found that three structures with D-2d, C-s, and C-2v symmetry are close in energy and most stable. This agrees with the fact that three isomers have been isolated and purified for Sc-2@C-84. The predicted endohedral D-2d and C-s structures are consistent with the available experimental data. The structure and stability of Sc-2@C-74 are also calculated and compared. (C) 1997 Elsevier Science B.V.