MgCrPbO3 crystallizes in the monoclinic Cm space group. Mg(1) is bonded to one O(1) and four equivalent O(2) atoms to form distorted MgO5 trigonal bipyramids that share  a cornercorner with one Cr(1)O5 square pyramid, corners with four equivalent Mg(1)O5 trigonal bipyramids, and edges with four equivalent Cr(1)O5 square pyramids. Cr(1) is bonded to one O(1) and four equivalent O(2) atoms to form distorted CrO5 square pyramids that share corners with four equivalent Cr(1)O5 square pyramids,  a cornercorner with one Mg(1)O5 trigonal bipyramid, and edges with four equivalent Mg(1)O5 trigonal bipyramids. Pb(1) is bonded in a single-bond geometry to one O(1) atom. There are two inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Mg(1), one Cr(1), and one Pb(1) atom. In the second O site, O(2) is bonded in a rectangular see-saw-like geometry to two equivalent Mg(1) and two equivalent Cr(1) atoms.
MgCrPbO3 crystallizes in the monoclinic Cm space group. Mg(1) is bonded to one O(1) and four equivalent O(2) atoms to form distorted MgO5 trigonal bipyramids that share  a cornercorner with one Cr(1)O5 square pyramid, corners with four equivalent Mg(1)O5 trigonal bipyramids, and edges with four equivalent Cr(1)O5 square pyramids. The Mg(1)-O(1) bond length is 2.00 Å. There are two shorter (2.08 Å) and two longer (2.11 Å) Mg(1)-O(2) bond lengths. Cr(1) is bonded to one O(1) and four equivalent O(2) atoms to form distorted CrO5 square pyramids that share corners with four equivalent Cr(1)O5 square pyramids,  a cornercorner with one Mg(1)O5 trigonal bipyramid, and edges with four equivalent Mg(1)O5 trigonal bipyramids. The Cr(1)-O(1) bond length is 2.25 Å. There are two shorter (2.01 Å) and two longer (2.03 Å) Cr(1)-O(2) bond lengths. Pb(1) is bonded in a single-bond geometry to one O(1) atom. The Pb(1)-O(1) bond length is 2.28 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Mg(1), one Cr(1), and one Pb(1) atom. In the second O site, O(2) is bonded in a rectangular see-saw-like geometry to two equivalent Mg(1) and two equivalent Cr(1) atoms.