Investigations of Ni3AsVO8 (I) and Co3AsVO8 (II) by X-ray single cryst
al technique show that (I) and (II) are isotypic to Co3V2O8. They crys
tallize with orthorhombic symmetry, space group D2h18-Cmca, Z = 4. The
lattice constants are (I): a = 5.932; b = 11.324; c = 8.197 angstrom
(II): a = 6.021; b = 11.456; c = 8.266 angstrom. The point position of
the M5+ ions is occupied by As5+ and V5+ statistically.