MgTiZn(BiO3)2 crystallizes in the orthorhombic Amm2 space group. Mg(1) is bonded to two equivalent O(2) and two equivalent O(3) atoms to form distorted MgO4 tetrahedra that share corners with two equivalent Ti(1)O4 tetrahedra and  an edgeedge with one Ti(1)O4 tetrahedra. Ti(1) is bonded to two equivalent O(2) and two equivalent O(3) atoms to form TiO4 tetrahedra that share corners with two equivalent Mg(1)O4 tetrahedra and  an edgeedge with one Mg(1)O4 tetrahedra. Zn(1) is bonded in a square co-planar geometry to two equivalent O(1) and two equivalent O(3) atoms. Bi(1) is bonded in a 2-coordinate geometry to two equivalent O(1) atoms. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal non-coplanar geometry to one Zn(1) and two equivalent Bi(1) atoms. In the second O site, O(2) is bonded in a linear geometry to one Mg(1) and one Ti(1) atom. In the third O site, O(3) is bonded in a distorted T-shaped geometry to one Mg(1), one Ti(1), and one Zn(1) atom.
MgTiZn(BiO3)2 crystallizes in the orthorhombic Amm2 space group. Mg(1) is bonded to two equivalent O(2) and two equivalent O(3) atoms to form distorted MgO4 tetrahedra that share corners with two equivalent Ti(1)O4 tetrahedra and  an edgeedge with one Ti(1)O4 tetrahedra. Both Mg(1)-O(2) bond lengths are 1.93 Å. Both Mg(1)-O(3) bond lengths are 2.02 Å. Ti(1) is bonded to two equivalent O(2) and two equivalent O(3) atoms to form TiO4 tetrahedra that share corners with two equivalent Mg(1)O4 tetrahedra and  an edgeedge with one Mg(1)O4 tetrahedra. Both Ti(1)-O(2) bond lengths are 1.81 Å. Both Ti(1)-O(3) bond lengths are 1.87 Å. Zn(1) is bonded in a square co-planar geometry to two equivalent O(1) and two equivalent O(3) atoms. Both Zn(1)-O(1) bond lengths are 1.96 Å. Both Zn(1)-O(3) bond lengths are 2.02 Å. Bi(1) is bonded in a 2-coordinate geometry to two equivalent O(1) atoms. Both Bi(1)-O(1) bond lengths are 2.23 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal non-coplanar geometry to one Zn(1) and two equivalent Bi(1) atoms. In the second O site, O(2) is bonded in a linear geometry to one Mg(1) and one Ti(1) atom. In the third O site, O(3) is bonded in a distorted T-shaped geometry to one Mg(1), one Ti(1), and one Zn(1) atom.