GeTe(2)O(6), a germanium tellurate(IV) with an open framework.

The structure of an already evidenced but still uncharacterized GeTe(2)O(6) phase consists of isolated GeO(6) octahedra connected via isolated TeO(3) units. The germanium cations occupy a site with 1 symmetry. The Te and O atoms are in general positions of the P2(1)/n space group. This structure corresponds to a new type of tetravalent tellurate and is different from other AB(2)X(6) structures in which the B cation presents a stereochemically active electronic lone pair. It derives from the pseudo-hexagonal MI(2)O(6) (M = Mg, Mn, Co and Fe) type by a strong monoclinic distortion caused by the much smaller size of Ge(4+) compared with the divalent M cations.