MgNbVO4 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(1), one O(4), and two equivalent O(2) atoms to form distorted MgO4 tetrahedra that share corners with four equivalent Nb(1)O6 octahedra, corners with two equivalent Mg(1)O4 tetrahedra, and  an edgeedge with one Nb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 8-56°. Nb(1) is bonded to one O(1), one O(4), two equivalent O(2), and two equivalent O(3) atoms to form NbO6 octahedra that share corners with four equivalent Mg(1)O4 tetrahedra, edges with two equivalent Nb(1)O6 octahedra, and  an edgeedge with one Mg(1)O4 tetrahedra. V(1) is bonded in a 5-coordinate geometry to one O(3), two equivalent O(1), and two equivalent O(4) atoms. There are four inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Nb(1), and two equivalent V(1) atoms. In the second O site, O(2) is bonded in a rectangular see-saw-like geometry to two equivalent Mg(1) and two equivalent Nb(1) atoms. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to two equivalent Nb(1) and one V(1) atom. In the fourth O site, O(4) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Nb(1), and two equivalent V(1) atoms.
MgNbVO4 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(1), one O(4), and two equivalent O(2) atoms to form distorted MgO4 tetrahedra that share corners with four equivalent Nb(1)O6 octahedra, corners with two equivalent Mg(1)O4 tetrahedra, and  an edgeedge with one Nb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 8-56°. The Mg(1)-O(1) bond length is 2.04 Å. The Mg(1)-O(4) bond length is 2.10 Å. There is one shorter (1.96 Å) and one longer (1.97 Å) Mg(1)-O(2) bond length. Nb(1) is bonded to one O(1), one O(4), two equivalent O(2), and two equivalent O(3) atoms to form NbO6 octahedra that share corners with four equivalent Mg(1)O4 tetrahedra, edges with two equivalent Nb(1)O6 octahedra, and  an edgeedge with one Mg(1)O4 tetrahedra. The Nb(1)-O(1) bond length is 2.06 Å. The Nb(1)-O(4) bond length is 1.99 Å. Both Nb(1)-O(2) bond lengths are 2.25 Å. Both Nb(1)-O(3) bond lengths are 2.09 Å. V(1) is bonded in a 5-coordinate geometry to one O(3), two equivalent O(1), and two equivalent O(4) atoms. The V(1)-O(3) bond length is 2.02 Å. There is one shorter (2.06 Å) and one longer (2.17 Å) V(1)-O(1) bond length. There is one shorter (2.16 Å) and one longer (2.18 Å) V(1)-O(4) bond length. There are four inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Nb(1), and two equivalent V(1) atoms. In the second O site, O(2) is bonded in a rectangular see-saw-like geometry to two equivalent Mg(1) and two equivalent Nb(1) atoms. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to two equivalent Nb(1) and one V(1) atom. In the fourth O site, O(4) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Nb(1), and two equivalent V(1) atoms.