Crystal structure of thorium metavanadate (Th(VO3)4)

The crystal structure of thorium metavanadate (Th(VO3)4) at ambient temperature is determined by Rietveld refinement of the powder X-ray diffraction data. This compound crystallizes in a tetragonal lattice, with the unit cell parameters: a = 8.5771(4) Å and c = 28.9739(4) Å, V = 2131.51(4) Å3 and Z = 8 (space group I41/a, no. 88). The detailed structural analysis reveals the presence of crystallographically distinct one thorium and seven oxygen atoms in the unit cell. There are two crystallographically distinct vanadium (V(1) and V(2)) atoms, each with tetrahedral coordination. The V(1)O4 and V(2)O4 polyhedra are connected via two corners forming chains of (VO3)nn−, along a- and b-axes in alternate layers. These layers of chains are stacked along the c-axis. The charge balance to the chains is provided by the Th4+ ions present in between the two successive layers of the (VO3)nn− chains. The overall crystal structure is quite similar to the pyroxene type silicates or vanadates. The further details of the crystal structure are explained in this manuscript.