MS(8)X(12) clusters are reminiscent of the elusive C-20 fullerene cage. Fullerene-like structures, embedded in two- or three-dimensional compounds have been recently characterized for (CU8Te12)(4-). Ab initio calculations are reported that confirm the structure of pentagonal dodecahedron for an isolated (Cu8Te12)(4-) cluster and for associated encapsulation complexes. Does it mean that all M(8)X(12) clusters are isostructural? Not necessarily. Similar ab initio calculations predict a different topology for the metallocarbohedrene M(8)C(12) clusters in relation with the pi-acceptor character of the C-C fragments.