The new compounds CuMgVO4 and AgMgVO4 have been synthesized by a solid state reaction route. Their crystal structures were determined from single-crystal X-ray diffraction data. CuMgVO4 crystallizes with Na2CrO4-type structure with space group Cmcm, a = 5.6932 (10), b = 8.7055 (15), c = 6.2789 (10) angstrom, V = 311.20 (9) angstrom(3), and Z = 4, whereas AgMgVO4 crystallizes in the maricite-type structure with space group Pnma, a = 9.4286 (14), b = 6.7465 (10), c = 5.3360 (8) angstrom, V = 339.42 (9) angstrom(3), and Z = 4. Both structures of CuMgVO4, and AgMgVO4 contain MgO4 chains made up of edge-sharing MgO6 octahedra. In CuMgVO4 the MgO4 chains are interconnected through CuVO4 double chains made up of VO4 and CuO4 tetrahedra sharing corners and edges, however in AgMgVO4 the chains are interlinked by the VO4 and AgO4 tetrahedra sharing only corners. (C) 2016 Elsevier B.V. All rights reserved.