MgV4Sb2(PO4)6 crystallizes in the monoclinic C2 space group. Mg(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(6) atoms to form distorted MgO6 pentagonal pyramids that share corners with two equivalent P(2)O4 tetrahedra, corners with two equivalent P(3)O4 tetrahedra,  an edgeedge with one P(1)O4 tetrahedra, and faces with two equivalent V(1)O6 octahedra. There are two inequivalent V sites. In the first V site, V(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(6), and one O(7) atom to form distorted VO6 octahedra that share  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(4)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, corners with two equivalent P(3)O4 tetrahedra, and  a faceface with one Mg(1)O6 pentagonal pyramid. In the second V site, V(2) is bonded to one O(10), one O(11), one O(12), one O(5), one O(8), and one O(9) atom to form VO6 octahedra that share  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(4)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, and corners with two equivalent P(3)O4 tetrahedra. Sb(1) is bonded in a 6-coordinate geometry to one O(10), one O(12), one O(3), one O(6), one O(7), and one O(8) atom. There are four inequivalent P sites. In the first P site, P(1) is bonded to two equivalent O(3) and two equivalent O(5) atoms to form PO4 tetrahedra that share corners with two equivalent V(1)O6 octahedra, corners with two equivalent V(2)O6 octahedra, and  an edgeedge with one Mg(1)O6 pentagonal pyramid. The corner-sharing octahedral tilt angles range from 30-49°. In the second P site, P(2) is bonded to one O(11), one O(6), one O(7), and one O(9) atom to form PO4 tetrahedra that share corners with two equivalent V(1)O6 octahedra, corners with two equivalent V(2)O6 octahedra, and  a cornercorner with one Mg(1)O6 pentagonal pyramid. The corner-sharing octahedral tilt angles range from 29-50°. In the third P site, P(3) is bonded to one O(10), one O(2), one O(4), and one O(8) atom to form PO4 tetrahedra that share corners with two equivalent V(1)O6 octahedra, corners with two equivalent V(2)O6 octahedra, and  a cornercorner with one Mg(1)O6 pentagonal pyramid. The corner-sharing octahedral tilt angles range from 9-52°. In the fourth P site, P(4) is bonded to two equivalent O(1) and two equivalent O(12) atoms to form PO4 tetrahedra that share corners with two equivalent V(1)O6 octahedra and corners with two equivalent V(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 33-47°. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one V(1) and one P(4) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Mg(1), one V(1), and one P(3) atom. In the third O site, O(3) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one V(1), one Sb(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a linear geometry to one V(1) and one P(3) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one V(2) and one P(1) atom. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to one Mg(1), one V(1), one Sb(1), and one P(2) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one V(1), one Sb(1), and one P(2) atom. In the eighth O site, O(8) is bonded in a 3-coordinate geometry to one V(2), one Sb(1), and one P(3) atom. In the ninth O site, O(9) is bonded in a bent 150 degrees geometry to one V(2) and one P(2) atom. In the tenth O site, O(10) is bonded in a 3-coordinate geometry to one V(2), one Sb(1), and one P(3) atom. In the eleventh O site, O(11) is bonded in a bent 150 degrees geometry to one V(2) and one P(2) atom. In the twelfth O site, O(12) is bonded in a 3-coordinate geometry to one V(2), one Sb(1), and one P(4) atom.
MgV4Sb2(PO4)6 crystallizes in the monoclinic C2 space group. Mg(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(6) atoms to form distorted MgO6 pentagonal pyramids that share corners with two equivalent P(2)O4 tetrahedra, corners with two equivalent P(3)O4 tetrahedra,  an edgeedge with one P(1)O4 tetrahedra, and faces with two equivalent V(1)O6 octahedra. Both Mg(1)-O(2) bond lengths are 2.13 Å. Both Mg(1)-O(3) bond lengths are 2.16 Å. Both Mg(1)-O(6) bond lengths are 2.18 Å. There are two inequivalent V sites. In the first V site, V(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(6), and one O(7) atom to form distorted VO6 octahedra that share  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(4)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, corners with two equivalent P(3)O4 tetrahedra, and  a faceface with one Mg(1)O6 pentagonal pyramid. The V(1)-O(1) bond length is 2.10 Å. The V(1)-O(2) bond length is 2.28 Å. The V(1)-O(3) bond length is 2.16 Å. The V(1)-O(4) bond length is 2.13 Å. The V(1)-O(6) bond length is 2.30 Å. The V(1)-O(7) bond length is 2.20 Å. In the second V site, V(2) is bonded to one O(10), one O(11), one O(12), one O(5), one O(8), and one O(9) atom to form VO6 octahedra that share  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(4)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, and corners with two equivalent P(3)O4 tetrahedra. The V(2)-O(10) bond length is 2.12 Å. The V(2)-O(11) bond length is 1.92 Å. The V(2)-O(12) bond length is 2.08 Å. The V(2)-O(5) bond length is 1.95 Å. The V(2)-O(8) bond length is 2.14 Å. The V(2)-O(9) bond length is 2.00 Å. Sb(1) is bonded in a 6-coordinate geometry to one O(10), one O(12), one O(3), one O(6), one O(7), and one O(8) atom. The Sb(1)-O(10) bond length is 2.23 Å. The Sb(1)-O(12) bond length is 2.19 Å. The Sb(1)-O(3) bond length is 2.57 Å. The Sb(1)-O(6) bond length is 2.63 Å. The Sb(1)-O(7) bond length is 2.43 Å. The Sb(1)-O(8) bond length is 2.24 Å. There are four inequivalent P sites. In the first P site, P(1) is bonded to two equivalent O(3) and two equivalent O(5) atoms to form PO4 tetrahedra that share corners with two equivalent V(1)O6 octahedra, corners with two equivalent V(2)O6 octahedra, and  an edgeedge with one Mg(1)O6 pentagonal pyramid. The corner-sharing octahedral tilt angles range from 30-49°. Both P(1)-O(3) bond lengths are 1.58 Å. Both P(1)-O(5) bond lengths are 1.52 Å. In the second P site, P(2) is bonded to one O(11), one O(6), one O(7), and one O(9) atom to form PO4 tetrahedra that share corners with two equivalent V(1)O6 octahedra, corners with two equivalent V(2)O6 octahedra, and  a cornercorner with one Mg(1)O6 pentagonal pyramid. The corner-sharing octahedral tilt angles range from 29-50°. The P(2)-O(11) bond length is 1.53 Å. The P(2)-O(6) bond length is 1.59 Å. The P(2)-O(7) bond length is 1.55 Å. The P(2)-O(9) bond length is 1.53 Å. In the third P site, P(3) is bonded to one O(10), one O(2), one O(4), and one O(8) atom to form PO4 tetrahedra that share corners with two equivalent V(1)O6 octahedra, corners with two equivalent V(2)O6 octahedra, and  a cornercorner with one Mg(1)O6 pentagonal pyramid. The corner-sharing octahedral tilt angles range from 9-52°. The P(3)-O(10) bond length is 1.61 Å. The P(3)-O(2) bond length is 1.54 Å. The P(3)-O(4) bond length is 1.49 Å. The P(3)-O(8) bond length is 1.59 Å. In the fourth P site, P(4) is bonded to two equivalent O(1) and two equivalent O(12) atoms to form PO4 tetrahedra that share corners with two equivalent V(1)O6 octahedra and corners with two equivalent V(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 33-47°. Both P(4)-O(1) bond lengths are 1.50 Å. Both P(4)-O(12) bond lengths are 1.61 Å. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one V(1) and one P(4) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Mg(1), one V(1), and one P(3) atom. In the third O site, O(3) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one V(1), one Sb(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a linear geometry to one V(1) and one P(3) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one V(2) and one P(1) atom. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to one Mg(1), one V(1), one Sb(1), and one P(2) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one V(1), one Sb(1), and one P(2) atom. In the eighth O site, O(8) is bonded in a 3-coordinate geometry to one V(2), one Sb(1), and one P(3) atom. In the ninth O site, O(9) is bonded in a bent 150 degrees geometry to one V(2) and one P(2) atom. In the tenth O site, O(10) is bonded in a 3-coordinate geometry to one V(2), one Sb(1), and one P(3) atom. In the eleventh O site, O(11) is bonded in a bent 150 degrees geometry to one V(2) and one P(2) atom. In the twelfth O site, O(12) is bonded in a 3-coordinate geometry to one V(2), one Sb(1), and one P(4) atom.