A DFT study of the heterofullerenes Sc3N@C79B, Sc3N@C79N, and Sc3N@C78BN

Based on calculations using density functional theory, we investigated the relative stabilities of the candidates for the most stable isomers of Sc3N@C79B, Sc3N@C79N, and Sc3N@C78BN. Judicious choices were applied to select stable isomers based on the electrostatic interaction between the Sc3N cluster and polar bonds of the cage. We predict that Sc3N@C80 can be doped with a boron atom or with a BN group substitutionally better than C60, suggesting that Sc3N@C79B and Sc3N@C78 BN could be produced in macroscopic amounts. As in the case of the substitution in Sc3N@C68, the feasibility of the B-substitution can be explained in terms of the electrostatic stabilization alone. However, we find that the BN-substitution is governed by a local preference complemented by the electrostatic effects. We also find that those substitutions restrict the rotation of the Sc3N cluster inside the cages to a certain degree, which is clearly different from the case of free rotation of the cluster in the undoped cage.