MgTiZn(BiO3)2 crystallizes in the monoclinic Cm space group. Mg(1) is bonded in a distorted bent 120 degrees geometry to one O(1) and one O(3) atom. Ti(1) is bonded to one O(1), one O(4), one O(5), and two equivalent O(2) atoms to form distorted TiO5 trigonal bipyramids that share corners with three equivalent Zn(1)O4 tetrahedra. Zn(1) is bonded to one O(3), one O(5), and two equivalent O(2) atoms to form ZnO4 tetrahedra that share corners with three equivalent Ti(1)O5 trigonal bipyramids. Bi(1) is bonded in a 5-coordinate geometry to one O(1), one O(2), one O(3), one O(4), and one O(5) atom. There are five inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), one Ti(1), and two equivalent Bi(1) atoms to form OMgTiBi2 tetrahedra that share corners with three equivalent O(3)MgZnBi2 tetrahedra and corners with three equivalent O(5)TiZnBi2 tetrahedra. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Ti(1), one Zn(1), and one Bi(1) atom. In the third O site, O(3) is bonded to one Mg(1), one Zn(1), and two equivalent Bi(1) atoms to form distorted OMgZnBi2 tetrahedra that share  a cornercorner with one O(5)TiZnBi2 tetrahedra, corners with three equivalent O(1)MgTiBi2 tetrahedra, and  an edgeedge with one O(5)TiZnBi2 tetrahedra. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to one Ti(1) and two equivalent Bi(1) atoms. In the fifth O site, O(5) is bonded to one Ti(1), one Zn(1), and two equivalent Bi(1) atoms to form distorted OTiZnBi2 tetrahedra that share  a cornercorner with one O(3)MgZnBi2 tetrahedra, corners with three equivalent O(1)MgTiBi2 tetrahedra, and  an edgeedge with one O(3)MgZnBi2 tetrahedra.
MgTiZn(BiO3)2 crystallizes in the monoclinic Cm space group. Mg(1) is bonded in a distorted bent 120 degrees geometry to one O(1) and one O(3) atom. The Mg(1)-O(1) bond length is 2.02 Å. The Mg(1)-O(3) bond length is 1.96 Å. Ti(1) is bonded to one O(1), one O(4), one O(5), and two equivalent O(2) atoms to form distorted TiO5 trigonal bipyramids that share corners with three equivalent Zn(1)O4 tetrahedra. The Ti(1)-O(1) bond length is 2.14 Å. The Ti(1)-O(4) bond length is 1.76 Å. The Ti(1)-O(5) bond length is 1.94 Å. Both Ti(1)-O(2) bond lengths are 1.96 Å. Zn(1) is bonded to one O(3), one O(5), and two equivalent O(2) atoms to form ZnO4 tetrahedra that share corners with three equivalent Ti(1)O5 trigonal bipyramids. The Zn(1)-O(3) bond length is 1.96 Å. The Zn(1)-O(5) bond length is 1.98 Å. Both Zn(1)-O(2) bond lengths are 2.05 Å. Bi(1) is bonded in a 5-coordinate geometry to one O(1), one O(2), one O(3), one O(4), and one O(5) atom. The Bi(1)-O(1) bond length is 2.36 Å. The Bi(1)-O(2) bond length is 2.38 Å. The Bi(1)-O(3) bond length is 2.52 Å. The Bi(1)-O(4) bond length is 2.56 Å. The Bi(1)-O(5) bond length is 2.40 Å. There are five inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), one Ti(1), and two equivalent Bi(1) atoms to form OMgTiBi2 tetrahedra that share corners with three equivalent O(3)MgZnBi2 tetrahedra and corners with three equivalent O(5)TiZnBi2 tetrahedra. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Ti(1), one Zn(1), and one Bi(1) atom. In the third O site, O(3) is bonded to one Mg(1), one Zn(1), and two equivalent Bi(1) atoms to form distorted OMgZnBi2 tetrahedra that share  a cornercorner with one O(5)TiZnBi2 tetrahedra, corners with three equivalent O(1)MgTiBi2 tetrahedra, and  an edgeedge with one O(5)TiZnBi2 tetrahedra. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to one Ti(1) and two equivalent Bi(1) atoms. In the fifth O site, O(5) is bonded to one Ti(1), one Zn(1), and two equivalent Bi(1) atoms to form distorted OTiZnBi2 tetrahedra that share  a cornercorner with one O(3)MgZnBi2 tetrahedra, corners with three equivalent O(1)MgTiBi2 tetrahedra, and  an edgeedge with one O(3)MgZnBi2 tetrahedra.