MgYSb(PbO3)2 crystallizes in the monoclinic Cm space group. Mg(1) is bonded to one O(4), two equivalent O(1), and two equivalent O(2) atoms to form distorted MgO5 trigonal bipyramids that share  an edgeedge with one Y(1)O6 octahedra and  a faceface with one Y(1)O6 octahedra. Y(1) is bonded to one O(3), one O(4), two equivalent O(1), and two equivalent O(2) atoms to form YO6 octahedra that share  an edgeedge with one Mg(1)O5 trigonal bipyramid and  a faceface with one Mg(1)O5 trigonal bipyramid. There are two inequivalent Pb sites. In the first Pb site, Pb(1) is bonded in a distorted trigonal non-coplanar geometry to one O(4) and two equivalent O(1) atoms. In the second Pb site, Pb(2) is bonded in a 3-coordinate geometry to one O(3) and two equivalent O(1) atoms. Sb(1) is bonded in a distorted T-shaped geometry to one O(3) and two equivalent O(2) 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 Y(1), one Pb(1), and one Pb(2) atom. In the second O site, O(2) is bonded in a T-shaped geometry to one Mg(1), one Y(1), and one Sb(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Y(1), one Pb(2), and one Sb(1) atom. In the fourth O site, O(4) is bonded in a T-shaped geometry to one Mg(1), one Y(1), and one Pb(1) atom.
MgYSb(PbO3)2 crystallizes in the monoclinic Cm space group. Mg(1) is bonded to one O(4), two equivalent O(1), and two equivalent O(2) atoms to form distorted MgO5 trigonal bipyramids that share  an edgeedge with one Y(1)O6 octahedra and  a faceface with one Y(1)O6 octahedra. The Mg(1)-O(4) bond length is 2.01 Å. Both Mg(1)-O(1) bond lengths are 2.18 Å. Both Mg(1)-O(2) bond lengths are 2.17 Å. Y(1) is bonded to one O(3), one O(4), two equivalent O(1), and two equivalent O(2) atoms to form YO6 octahedra that share  an edgeedge with one Mg(1)O5 trigonal bipyramid and  a faceface with one Mg(1)O5 trigonal bipyramid. The Y(1)-O(3) bond length is 2.31 Å. The Y(1)-O(4) bond length is 2.27 Å. Both Y(1)-O(1) bond lengths are 2.34 Å. Both Y(1)-O(2) bond lengths are 2.29 Å. There are two inequivalent Pb sites. In the first Pb site, Pb(1) is bonded in a distorted trigonal non-coplanar geometry to one O(4) and two equivalent O(1) atoms. The Pb(1)-O(4) bond length is 2.26 Å. Both Pb(1)-O(1) bond lengths are 2.34 Å. In the second Pb site, Pb(2) is bonded in a 3-coordinate geometry to one O(3) and two equivalent O(1) atoms. The Pb(2)-O(3) bond length is 2.49 Å. Both Pb(2)-O(1) bond lengths are 2.28 Å. Sb(1) is bonded in a distorted T-shaped geometry to one O(3) and two equivalent O(2) atoms. The Sb(1)-O(3) bond length is 2.03 Å. Both Sb(1)-O(2) bond lengths are 2.03 Å. 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 Y(1), one Pb(1), and one Pb(2) atom. In the second O site, O(2) is bonded in a T-shaped geometry to one Mg(1), one Y(1), and one Sb(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Y(1), one Pb(2), and one Sb(1) atom. In the fourth O site, O(4) is bonded in a T-shaped geometry to one Mg(1), one Y(1), and one Pb(1) atom.