MgTiZn(BiO3)2 crystallizes in the orthorhombic Pmm2 space group. Mg(1) is bonded in a 4-coordinate geometry to one Bi(1) and four equivalent O(1) atoms. Ti(1) is bonded in a 5-coordinate geometry to one O(3) and four equivalent O(1) atoms. Zn(1) is bonded in a 5-coordinate geometry to one O(2) and four equivalent O(1) atoms. There are two inequivalent Bi sites. In the first Bi site, Bi(1) is bonded to one Mg(1), two equivalent O(2), and two equivalent O(3) atoms to form distorted BiMgO4 square pyramids that share corners with four equivalent Bi(1)MgO4 square pyramids and corners with four equivalent O(1)MgTiZnBi tetrahedra. In the second Bi site, Bi(2) is bonded in a 4-coordinate geometry to four equivalent O(1) atoms. There are three inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), one Ti(1), one Zn(1), and one Bi(2) atom to form distorted OMgTiZnBi tetrahedra that share  a cornercorner with one Bi(1)MgO4 square pyramid, corners with four equivalent O(1)MgTiZnBi tetrahedra, and edges with four equivalent O(1)MgTiZnBi tetrahedra. In the second O site, O(2) is bonded in a T-shaped geometry to one Zn(1) and two equivalent Bi(1) atoms. In the third O site, O(3) is bonded in a distorted single-bond geometry to one Ti(1) and two equivalent Bi(1) atoms.
MgTiZn(BiO3)2 crystallizes in the orthorhombic Pmm2 space group. Mg(1) is bonded in a 4-coordinate geometry to one Bi(1) and four equivalent O(1) atoms. The Mg(1)-Bi(1) bond length is 2.90 Å. All Mg(1)-O(1) bond lengths are 1.99 Å. Ti(1) is bonded in a 5-coordinate geometry to one O(3) and four equivalent O(1) atoms. The Ti(1)-O(3) bond length is 1.79 Å. All Ti(1)-O(1) bond lengths are 1.98 Å. Zn(1) is bonded in a 5-coordinate geometry to one O(2) and four equivalent O(1) atoms. The Zn(1)-O(2) bond length is 1.93 Å. All Zn(1)-O(1) bond lengths are 2.15 Å. There are two inequivalent Bi sites. In the first Bi site, Bi(1) is bonded to one Mg(1), two equivalent O(2), and two equivalent O(3) atoms to form distorted BiMgO4 square pyramids that share corners with four equivalent Bi(1)MgO4 square pyramids and corners with four equivalent O(1)MgTiZnBi tetrahedra. Both Bi(1)-O(2) bond lengths are 2.63 Å. Both Bi(1)-O(3) bond lengths are 2.69 Å. In the second Bi site, Bi(2) is bonded in a 4-coordinate geometry to four equivalent O(1) atoms. All Bi(2)-O(1) bond lengths are 2.22 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), one Ti(1), one Zn(1), and one Bi(2) atom to form distorted OMgTiZnBi tetrahedra that share  a cornercorner with one Bi(1)MgO4 square pyramid, corners with four equivalent O(1)MgTiZnBi tetrahedra, and edges with four equivalent O(1)MgTiZnBi tetrahedra. In the second O site, O(2) is bonded in a T-shaped geometry to one Zn(1) and two equivalent Bi(1) atoms. In the third O site, O(3) is bonded in a distorted single-bond geometry to one Ti(1) and two equivalent Bi(1) atoms.