The langbeinite type Rb2TiY(PO4)(3)

Dirubidium titanium yttrium triphosphate belongs to the langbeinite structure type with a framework of Mo-6 octahedra (M = Ti, Y) sharing corners with PO4 tetrahedra and vice versa, creating cages in which the Rb+ cations are located. The compound exhibits mixed Ti/Y populations in the two crystallographically independent octahedral sites of symmetry 3. More than two-thirds of the yttrium is found in one site and the remaining amount in the other; this is caused by the difference in coordination for the two sites.