MgFe2(BiO3)2 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form MgO6 octahedra that share corners with three equivalent Fe(2)O6 octahedra, corners with three equivalent Bi(1)O6 octahedra, edges with three equivalent Bi(2)O6 octahedra,  a faceface with one Fe(2)O6 octahedra, and  a faceface with one Bi(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 43-47°. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a trigonal planar geometry to one O(1), one O(2), and one O(3) atom. In the second Fe site, Fe(2) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form FeO6 octahedra that share corners with three equivalent Mg(1)O6 octahedra, corners with three equivalent Bi(2)O6 octahedra, edges with three equivalent Bi(1)O6 octahedra,  a faceface with one Mg(1)O6 octahedra, and  a faceface with one Bi(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 43-49°. There are two inequivalent Bi sites. In the first Bi site, Bi(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form distorted BiO6 octahedra that share corners with three equivalent Mg(1)O6 octahedra, corners with six equivalent Bi(2)O6 octahedra, edges with three equivalent Fe(2)O6 octahedra, and  a faceface with one Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 37-66°. In the second Bi site, Bi(2) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form distorted BiO6 octahedra that share corners with three equivalent Fe(2)O6 octahedra, corners with six equivalent Bi(1)O6 octahedra, edges with three equivalent Mg(1)O6 octahedra, and  a faceface with one Fe(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 37-66°. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to one Mg(1), one Fe(1), one Fe(2), one Bi(1), and one Bi(2) atom. In the second O site, O(2) is bonded in a 5-coordinate geometry to one Mg(1), one Fe(1), one Fe(2), one Bi(1), and one Bi(2) atom. In the third O site, O(3) is bonded in a 5-coordinate geometry to one Mg(1), one Fe(1), one Fe(2), one Bi(1), and one Bi(2) atom. In the fourth O site, O(4) is bonded to one Mg(1), one Fe(2), one Bi(1), and one Bi(2) atom to form a mixture of distorted corner and edge-sharing OMgFeBi2 trigonal pyramids. In the fifth O site, O(5) is bonded to one Mg(1), one Fe(2), one Bi(1), and one Bi(2) atom to form a mixture of distorted corner and edge-sharing OMgFeBi2 trigonal pyramids. In the sixth O site, O(6) is bonded to one Mg(1), one Fe(2), one Bi(1), and one Bi(2) atom to form a mixture of distorted corner and edge-sharing OMgFeBi2 trigonal pyramids.
MgFe2(BiO3)2 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form MgO6 octahedra that share corners with three equivalent Fe(2)O6 octahedra, corners with three equivalent Bi(1)O6 octahedra, edges with three equivalent Bi(2)O6 octahedra,  a faceface with one Fe(2)O6 octahedra, and  a faceface with one Bi(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 43-47°. The Mg(1)-O(1) bond length is 2.26 Å. The Mg(1)-O(2) bond length is 2.28 Å. The Mg(1)-O(3) bond length is 2.18 Å. The Mg(1)-O(4) bond length is 2.17 Å. The Mg(1)-O(5) bond length is 2.10 Å. The Mg(1)-O(6) bond length is 2.12 Å. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a trigonal planar geometry to one O(1), one O(2), and one O(3) atom. The Fe(1)-O(1) bond length is 1.98 Å. The Fe(1)-O(2) bond length is 1.99 Å. The Fe(1)-O(3) bond length is 1.98 Å. In the second Fe site, Fe(2) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form FeO6 octahedra that share corners with three equivalent Mg(1)O6 octahedra, corners with three equivalent Bi(2)O6 octahedra, edges with three equivalent Bi(1)O6 octahedra,  a faceface with one Mg(1)O6 octahedra, and  a faceface with one Bi(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 43-49°. The Fe(2)-O(1) bond length is 2.35 Å. The Fe(2)-O(2) bond length is 2.15 Å. The Fe(2)-O(3) bond length is 2.42 Å. The Fe(2)-O(4) bond length is 2.11 Å. The Fe(2)-O(5) bond length is 2.21 Å. The Fe(2)-O(6) bond length is 2.23 Å. There are two inequivalent Bi sites. In the first Bi site, Bi(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form distorted BiO6 octahedra that share corners with three equivalent Mg(1)O6 octahedra, corners with six equivalent Bi(2)O6 octahedra, edges with three equivalent Fe(2)O6 octahedra, and  a faceface with one Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 37-66°. The Bi(1)-O(1) bond length is 2.49 Å. The Bi(1)-O(2) bond length is 2.59 Å. The Bi(1)-O(3) bond length is 2.60 Å. The Bi(1)-O(4) bond length is 2.27 Å. The Bi(1)-O(5) bond length is 2.28 Å. The Bi(1)-O(6) bond length is 2.27 Å. In the second Bi site, Bi(2) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form distorted BiO6 octahedra that share corners with three equivalent Fe(2)O6 octahedra, corners with six equivalent Bi(1)O6 octahedra, edges with three equivalent Mg(1)O6 octahedra, and  a faceface with one Fe(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 37-66°. The Bi(2)-O(1) bond length is 2.52 Å. The Bi(2)-O(2) bond length is 2.58 Å. The Bi(2)-O(3) bond length is 2.45 Å. The Bi(2)-O(4) bond length is 2.35 Å. The Bi(2)-O(5) bond length is 2.28 Å. The Bi(2)-O(6) bond length is 2.26 Å. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to one Mg(1), one Fe(1), one Fe(2), one Bi(1), and one Bi(2) atom. In the second O site, O(2) is bonded in a 5-coordinate geometry to one Mg(1), one Fe(1), one Fe(2), one Bi(1), and one Bi(2) atom. In the third O site, O(3) is bonded in a 5-coordinate geometry to one Mg(1), one Fe(1), one Fe(2), one Bi(1), and one Bi(2) atom. In the fourth O site, O(4) is bonded to one Mg(1), one Fe(2), one Bi(1), and one Bi(2) atom to form a mixture of distorted corner and edge-sharing OMgFeBi2 trigonal pyramids. In the fifth O site, O(5) is bonded to one Mg(1), one Fe(2), one Bi(1), and one Bi(2) atom to form a mixture of distorted corner and edge-sharing OMgFeBi2 trigonal pyramids. In the sixth O site, O(6) is bonded to one Mg(1), one Fe(2), one Bi(1), and one Bi(2) atom to form a mixture of distorted corner and edge-sharing OMgFeBi2 trigonal pyramids.