H -type Ce 2 [Si 2 O 7 ].

The title compound, dicerium(III) oxidodisilicate, Ce2 [Si2 O7 ], was obtained as a by-product in its H -type structure after attempts to synthesize CeSb2 O4 Cl from fused silica ampoules. It crystallizes isotypically with H -La2 [Si2 O7 ]. The four crystallographically distinct CeIII cations form distorted square anti-prisms, capped square anti-prisms, and bicapped square anti-prisms as coordination polyhedra consisting of oxygen atoms. Four crystallographically different silicon atoms recruit the centers of two different isolated [Si2 O7 ]6- units.