Electronic structure of endohedral Y@C82; an ab initio Hartree-Fock investigation

Parts of the potential energy surface of endohedral Y@C82 have been studied in a three-dimensional configuration space confined to the spatial degrees of freedom of Y. The optimized position of the endohedral atom is strongly off-center and corresponds to a pyracylene topology with Y located above a 6-6 bond connecting two pentagons. The calculated minimum is explained by the pocket structure of the C82 cage and the high acceptor capability of fullerence pentagons. We have employed a Hartree-Fock ab initio approach defined by a split-valence 3-21G double zeta basis to search for the optimized position of Y embedded in a C82 shell of C2 symmetry. The present computational results are compared with experimental data and findings of other quantum chemical calculations.