MgV2Ni(TeO5)2 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(1), one O(2), one O(3), one O(6), and one O(9) atom to form distorted MgO5 trigonal bipyramids that share corners with two equivalent V(1)O6 octahedra, corners with two equivalent Ni(1)O4 tetrahedra, and  a faceface with one V(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 33-49°. There are two inequivalent V sites. In the first V site, V(1) is bonded to one O(1), one O(10), one O(4), one O(5), one O(7), and one O(9) atom to form VO6 octahedra that share corners with two equivalent Ni(1)O4 tetrahedra, corners with two equivalent Mg(1)O5 trigonal bipyramids, and edges with two equivalent V(2)O6 octahedra. In the second V site, V(2) is bonded to one O(1), one O(10), one O(2), one O(4), one O(6), and one O(7) atom to form distorted VO6 octahedra that share corners with two equivalent Ni(1)O4 tetrahedra, edges with two equivalent V(1)O6 octahedra, and  a faceface with one Mg(1)O5 trigonal bipyramid. Ni(1) is bonded to one O(10), one O(2), one O(8), and one O(9) atom to form distorted NiO4 tetrahedra that share corners with two equivalent V(1)O6 octahedra, corners with two equivalent V(2)O6 octahedra, and corners with two equivalent Mg(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 37-63°. There are two inequivalent Te sites. In the first Te site, Te(1) is bonded in a 4-coordinate geometry to one O(3), one O(6), one O(7), and one O(8) atom. In the second Te site, Te(2) is bonded in a 4-coordinate geometry to one O(3), one O(4), one O(5), and one O(8) atom. There are ten inequivalent O sites. In the first O site, O(1) is bonded in a distorted T-shaped geometry to one Mg(1), one V(1), and one V(2) atom. In the second O site, O(2) is bonded in a distorted T-shaped geometry to one Mg(1), one V(2), and one Ni(1) atom. In the third O site, O(3) is bonded in a distorted trigonal non-coplanar geometry to one Mg(1), one Te(1), and one Te(2) atom. In the fourth O site, O(4) is bonded in a distorted trigonal non-coplanar geometry to one V(1), one V(2), and one Te(2) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one V(1) and one Te(2) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Mg(1), one V(2), and one Te(1) atom. In the seventh O site, O(7) is bonded in a distorted trigonal non-coplanar geometry to one V(1), one V(2), and one Te(1) atom. In the eighth O site, O(8) is bonded in a distorted trigonal non-coplanar geometry to one Ni(1), one Te(1), and one Te(2) atom. In the ninth O site, O(9) is bonded in a distorted trigonal planar geometry to one Mg(1), one V(1), and one Ni(1) atom. In the tenth O site, O(10) is bonded in a trigonal non-coplanar geometry to one V(1), one V(2), and one Ni(1) atom.
MgV2Ni(TeO5)2 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(1), one O(2), one O(3), one O(6), and one O(9) atom to form distorted MgO5 trigonal bipyramids that share corners with two equivalent V(1)O6 octahedra, corners with two equivalent Ni(1)O4 tetrahedra, and  a faceface with one V(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 33-49°. The Mg(1)-O(1) bond length is 1.99 Å. The Mg(1)-O(2) bond length is 2.01 Å. The Mg(1)-O(3) bond length is 2.01 Å. The Mg(1)-O(6) bond length is 2.22 Å. The Mg(1)-O(9) bond length is 2.03 Å. There are two inequivalent V sites. In the first V site, V(1) is bonded to one O(1), one O(10), one O(4), one O(5), one O(7), and one O(9) atom to form VO6 octahedra that share corners with two equivalent Ni(1)O4 tetrahedra, corners with two equivalent Mg(1)O5 trigonal bipyramids, and edges with two equivalent V(2)O6 octahedra. The V(1)-O(1) bond length is 1.88 Å. The V(1)-O(10) bond length is 2.04 Å. The V(1)-O(4) bond length is 2.12 Å. The V(1)-O(5) bond length is 1.98 Å. The V(1)-O(7) bond length is 2.06 Å. The V(1)-O(9) bond length is 1.82 Å. In the second V site, V(2) is bonded to one O(1), one O(10), one O(2), one O(4), one O(6), and one O(7) atom to form distorted VO6 octahedra that share corners with two equivalent Ni(1)O4 tetrahedra, edges with two equivalent V(1)O6 octahedra, and  a faceface with one Mg(1)O5 trigonal bipyramid. The V(2)-O(1) bond length is 2.06 Å. The V(2)-O(10) bond length is 1.91 Å. The V(2)-O(2) bond length is 1.82 Å. The V(2)-O(4) bond length is 1.96 Å. The V(2)-O(6) bond length is 2.32 Å. The V(2)-O(7) bond length is 1.98 Å. Ni(1) is bonded to one O(10), one O(2), one O(8), and one O(9) atom to form distorted NiO4 tetrahedra that share corners with two equivalent V(1)O6 octahedra, corners with two equivalent V(2)O6 octahedra, and corners with two equivalent Mg(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 37-63°. The Ni(1)-O(10) bond length is 1.96 Å. The Ni(1)-O(2) bond length is 1.95 Å. The Ni(1)-O(8) bond length is 1.96 Å. The Ni(1)-O(9) bond length is 1.99 Å. There are two inequivalent Te sites. In the first Te site, Te(1) is bonded in a 4-coordinate geometry to one O(3), one O(6), one O(7), and one O(8) atom. The Te(1)-O(3) bond length is 2.35 Å. The Te(1)-O(6) bond length is 1.91 Å. The Te(1)-O(7) bond length is 2.07 Å. The Te(1)-O(8) bond length is 1.94 Å. In the second Te site, Te(2) is bonded in a 4-coordinate geometry to one O(3), one O(4), one O(5), and one O(8) atom. The Te(2)-O(3) bond length is 1.95 Å. The Te(2)-O(4) bond length is 2.00 Å. The Te(2)-O(5) bond length is 1.88 Å. The Te(2)-O(8) bond length is 2.44 Å. There are ten inequivalent O sites. In the first O site, O(1) is bonded in a distorted T-shaped geometry to one Mg(1), one V(1), and one V(2) atom. In the second O site, O(2) is bonded in a distorted T-shaped geometry to one Mg(1), one V(2), and one Ni(1) atom. In the third O site, O(3) is bonded in a distorted trigonal non-coplanar geometry to one Mg(1), one Te(1), and one Te(2) atom. In the fourth O site, O(4) is bonded in a distorted trigonal non-coplanar geometry to one V(1), one V(2), and one Te(2) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one V(1) and one Te(2) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Mg(1), one V(2), and one Te(1) atom. In the seventh O site, O(7) is bonded in a distorted trigonal non-coplanar geometry to one V(1), one V(2), and one Te(1) atom. In the eighth O site, O(8) is bonded in a distorted trigonal non-coplanar geometry to one Ni(1), one Te(1), and one Te(2) atom. In the ninth O site, O(9) is bonded in a distorted trigonal planar geometry to one Mg(1), one V(1), and one Ni(1) atom. In the tenth O site, O(10) is bonded in a trigonal non-coplanar geometry to one V(1), one V(2), and one Ni(1) atom.