Short O-O distances in edge sharing PO4 tetrahedra and VO6 octahedra of the vanadyl-orthophosphate CaNi(VO)(PO4)(2)

Single crystals of the new compound CaNi(VO)(PO4)(2) have been prepared by solid state reactions below the melting point of the oxide mixture in evacuated quartz tubes. X-ray investigations led to orthorhombic symmetry, space group D-2h(16)-Pnma, a = 14.113(1), b = 6.408(1), c = 7.364(1) Angstrom, Z = 4. The crystal structure shows (1)(infinity)[NiO4] and (1)(infinity) [VO6P2O3] polyhedra chains closely related to analogous chains in the isotypic compound CdV2O(PO4)(2). The short V-O distance of 1.66 Angstrom indicates a vanadyl group as the main difference to CdV2O(PO4)(2). The short O-O distance of 2,395 Angstrom of the edge-sharing PO4 tetrahedra and VO6 octahedra is discussed.