The trimetallic nitride template (TNT) approach has been successfully utilized to prepare the new endohedral Lu3N@C80. Well-ordered crystals of Lu3N@C80⋅5 (o-xylene) and Sc3N@C80⋅5 (o-xylene) form upon cooling of o-xylene solutions of these endohedrals and they are isomorphous. Although the positions of the fullerene cage (which is fully ordered and located at a crystallographic center of symmetry) and the o-xylene molecules are nearly identical in these two structures, the positioning of the metal ions in the two crystals differ in significant ways. However, the expected difference in sizes of lutetium and scandium does not affect the dimensions of the C80 cage. Nevertheless, the positions of the metal atoms do produce a slight outward dislocation of the immediately adjacent carbon atoms.