MgV4(PbO6)2 crystallizes in the monoclinic Cm space group. Mg(1) is bonded in a 4-coordinate geometry to one O(3), one O(5), and two equivalent O(6) atoms. There are four inequivalent V sites. In the first V site, V(1) is bonded to one O(1), one O(5), one O(9), and two equivalent O(4) atoms to form a mixture of distorted corner and edge-sharing VO5 trigonal bipyramids. In the second V site, V(2) is bonded to one O(12), one O(2), one O(6), and two equivalent O(3) atoms to form distorted VO5 trigonal bipyramids that share corners with two equivalent Pb(2)O5 square pyramids and corners with two equivalent V(2)O5 trigonal bipyramids. In the third V site, V(3) is bonded in a 5-coordinate geometry to one O(10), one O(3), one O(8), and two equivalent O(2) atoms. In the fourth V site, V(4) is bonded to one O(11), one O(4), one O(7), and two equivalent O(1) atoms to form distorted VO5 trigonal bipyramids that share  a cornercorner with one Pb(2)O5 square pyramid, corners with two equivalent V(4)O5 trigonal bipyramids, and edges with two equivalent V(1)O5 trigonal bipyramids. There are two inequivalent Pb sites. In the first Pb site, Pb(1) is bonded in a 3-coordinate geometry to one O(8) and two equivalent O(9) atoms. In the second Pb site, Pb(2) is bonded to one O(7), two equivalent O(10), and two equivalent O(12) atoms to form PbO5 square pyramids that share  a cornercorner with one V(4)O5 trigonal bipyramid, corners with two equivalent V(2)O5 trigonal bipyramids, and edges with two equivalent Pb(2)O5 square pyramids. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a distorted T-shaped geometry to one V(1) and two equivalent V(4) atoms. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to one V(2) and two equivalent V(3) atoms. In the third O site, O(3) is bonded to one Mg(1), one V(3), and two equivalent V(2) atoms to form distorted corner-sharing OMgV3 tetrahedra. In the fourth O site, O(4) is bonded in a distorted trigonal non-coplanar geometry to one V(4) and two equivalent V(1) atoms. In the fifth O site, O(5) is bonded in a bent 120 degrees geometry to one Mg(1) and one V(1) atom. In the sixth O site, O(6) is bonded in a distorted T-shaped geometry to two equivalent Mg(1) and one V(2) atom. In the seventh O site, O(7) is bonded in a bent 150 degrees geometry to one V(4) and one Pb(2) atom. In the eighth O site, O(8) is bonded in a distorted bent 150 degrees geometry to one V(3) and one Pb(1) atom. In the ninth O site, O(9) is bonded in a distorted trigonal planar geometry to one V(1) and two equivalent Pb(1) atoms. In the tenth O site, O(10) is bonded in a distorted single-bond geometry to one V(3) and two equivalent Pb(2) atoms. In the eleventh O site, O(11) is bonded in a single-bond geometry to one V(4) atom. In the twelfth O site, O(12) is bonded in a distorted single-bond geometry to one V(2) and two equivalent Pb(2) atoms.
MgV4(PbO6)2 crystallizes in the monoclinic Cm space group. Mg(1) is bonded in a 4-coordinate geometry to one O(3), one O(5), and two equivalent O(6) atoms. The Mg(1)-O(3) bond length is 2.10 Å. The Mg(1)-O(5) bond length is 1.93 Å. Both Mg(1)-O(6) bond lengths are 2.02 Å. There are four inequivalent V sites. In the first V site, V(1) is bonded to one O(1), one O(5), one O(9), and two equivalent O(4) atoms to form a mixture of distorted corner and edge-sharing VO5 trigonal bipyramids. The V(1)-O(1) bond length is 1.96 Å. The V(1)-O(5) bond length is 1.74 Å. The V(1)-O(9) bond length is 1.86 Å. Both V(1)-O(4) bond lengths are 1.97 Å. In the second V site, V(2) is bonded to one O(12), one O(2), one O(6), and two equivalent O(3) atoms to form distorted VO5 trigonal bipyramids that share corners with two equivalent Pb(2)O5 square pyramids and corners with two equivalent V(2)O5 trigonal bipyramids. The V(2)-O(12) bond length is 1.74 Å. The V(2)-O(2) bond length is 1.96 Å. The V(2)-O(6) bond length is 1.87 Å. Both V(2)-O(3) bond lengths are 1.97 Å. In the third V site, V(3) is bonded in a 5-coordinate geometry to one O(10), one O(3), one O(8), and two equivalent O(2) atoms. The V(3)-O(10) bond length is 1.69 Å. The V(3)-O(3) bond length is 2.03 Å. The V(3)-O(8) bond length is 1.67 Å. Both V(3)-O(2) bond lengths are 1.96 Å. In the fourth V site, V(4) is bonded to one O(11), one O(4), one O(7), and two equivalent O(1) atoms to form distorted VO5 trigonal bipyramids that share  a cornercorner with one Pb(2)O5 square pyramid, corners with two equivalent V(4)O5 trigonal bipyramids, and edges with two equivalent V(1)O5 trigonal bipyramids. The V(4)-O(11) bond length is 1.68 Å. The V(4)-O(4) bond length is 1.97 Å. The V(4)-O(7) bond length is 1.71 Å. Both V(4)-O(1) bond lengths are 1.95 Å. There are two inequivalent Pb sites. In the first Pb site, Pb(1) is bonded in a 3-coordinate geometry to one O(8) and two equivalent O(9) atoms. The Pb(1)-O(8) bond length is 2.33 Å. Both Pb(1)-O(9) bond lengths are 2.33 Å. In the second Pb site, Pb(2) is bonded to one O(7), two equivalent O(10), and two equivalent O(12) atoms to form PbO5 square pyramids that share  a cornercorner with one V(4)O5 trigonal bipyramid, corners with two equivalent V(2)O5 trigonal bipyramids, and edges with two equivalent Pb(2)O5 square pyramids. The Pb(2)-O(7) bond length is 2.26 Å. Both Pb(2)-O(10) bond lengths are 2.61 Å. Both Pb(2)-O(12) bond lengths are 2.50 Å. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a distorted T-shaped geometry to one V(1) and two equivalent V(4) atoms. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to one V(2) and two equivalent V(3) atoms. In the third O site, O(3) is bonded to one Mg(1), one V(3), and two equivalent V(2) atoms to form distorted corner-sharing OMgV3 tetrahedra. In the fourth O site, O(4) is bonded in a distorted trigonal non-coplanar geometry to one V(4) and two equivalent V(1) atoms. In the fifth O site, O(5) is bonded in a bent 120 degrees geometry to one Mg(1) and one V(1) atom. In the sixth O site, O(6) is bonded in a distorted T-shaped geometry to two equivalent Mg(1) and one V(2) atom. In the seventh O site, O(7) is bonded in a bent 150 degrees geometry to one V(4) and one Pb(2) atom. In the eighth O site, O(8) is bonded in a distorted bent 150 degrees geometry to one V(3) and one Pb(1) atom. In the ninth O site, O(9) is bonded in a distorted trigonal planar geometry to one V(1) and two equivalent Pb(1) atoms. In the tenth O site, O(10) is bonded in a distorted single-bond geometry to one V(3) and two equivalent Pb(2) atoms. In the eleventh O site, O(11) is bonded in a single-bond geometry to one V(4) atom. In the twelfth O site, O(12) is bonded in a distorted single-bond geometry to one V(2) and two equivalent Pb(2) atoms.