SHORT O-O DISTANCES IN EDGE-SHARING PO4 T ETRAHEDRA AND VO6 OCTAHEDRAOF THE VANADYL-ORTHOPHOSPHATE CANI(VO)(PO4)(2)

Single crystals of the new compound CaNi(VO)(PO4)(2) have been prepare d by solid state reactions below the melting point of the oxide mixtur e 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)[Ni O4] and (1)(infinity) [VO6P2O3] polyhedra chains closely related to an alogous chains in the isotypic compound CdV2O(PO4)(2). The short V-O d istance of 1.66 Angstrom indicates a vanadyl group as the main differe nce to CdV2O(PO4)(2). The short O-O distance of 2,395 Angstrom of the edge-sharing PO4 tetrahedra and VO6 octahedra is discussed.