Mg3Fe2O5 is Caswellsilverite-like structured and crystallizes in the triclinic P-1 space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form MgO6 octahedra that share corners with two equivalent Mg(1)O6 octahedra, corners with two equivalent Mg(2)O6 octahedra, corners with two equivalent Fe(1)O6 octahedra, edges with six equivalent Mg(2)O6 octahedra, and edges with six equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-7°. In the second Mg site, Mg(2) is bonded to one O(1), two equivalent O(2), and three equivalent O(3) atoms to form MgO6 octahedra that share  a cornercorner with one Mg(1)O6 octahedra, corners with two equivalent Fe(1)O6 octahedra, corners with three equivalent Mg(2)O6 octahedra, edges with three equivalent Mg(1)O6 octahedra, edges with three equivalent Mg(2)O6 octahedra, and edges with six equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-9°. Fe(1) is bonded to one O(1), two equivalent O(3), and three equivalent O(2) atoms to form FeO6 octahedra that share  a cornercorner with one Mg(1)O6 octahedra, corners with two equivalent Mg(2)O6 octahedra, corners with three equivalent Fe(1)O6 octahedra, edges with three equivalent Mg(1)O6 octahedra, edges with three equivalent Fe(1)O6 octahedra, and edges with six equivalent Mg(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-12°. There are three inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Mg(1), two equivalent Mg(2), and two equivalent Fe(1) atoms to form OMg4Fe2 octahedra that share corners with two equivalent O(2)Mg3Fe3 octahedra, corners with two equivalent O(1)Mg4Fe2 octahedra, corners with two equivalent O(3)Mg4Fe2 octahedra, edges with six equivalent O(2)Mg3Fe3 octahedra, and edges with six equivalent O(3)Mg4Fe2 octahedra. The corner-sharing octahedral tilt angles range from 0-11°. In the second O site, O(2) is bonded to one Mg(1), two equivalent Mg(2), and three equivalent Fe(1) atoms to form OMg3Fe3 octahedra that share  a cornercorner with one O(1)Mg4Fe2 octahedra, corners with two equivalent O(3)Mg4Fe2 octahedra, corners with three equivalent O(2)Mg3Fe3 octahedra, edges with three equivalent O(2)Mg3Fe3 octahedra, edges with three equivalent O(1)Mg4Fe2 octahedra, and edges with six equivalent O(3)Mg4Fe2 octahedra. The corner-sharing octahedral tilt angles range from 0-12°. In the third O site, O(3) is bonded to one Mg(1), three equivalent Mg(2), and two equivalent Fe(1) atoms to form OMg4Fe2 octahedra that share  a cornercorner with one O(1)Mg4Fe2 octahedra, corners with two equivalent O(2)Mg3Fe3 octahedra, corners with three equivalent O(3)Mg4Fe2 octahedra, edges with three equivalent O(1)Mg4Fe2 octahedra, edges with three equivalent O(3)Mg4Fe2 octahedra, and edges with six equivalent O(2)Mg3Fe3 octahedra. The corner-sharing octahedral tilt angles range from 0-11°.
Mg3Fe2O5 is Caswellsilverite-like structured and crystallizes in the triclinic P-1 space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form MgO6 octahedra that share corners with two equivalent Mg(1)O6 octahedra, corners with two equivalent Mg(2)O6 octahedra, corners with two equivalent Fe(1)O6 octahedra, edges with six equivalent Mg(2)O6 octahedra, and edges with six equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-7°. Both Mg(1)-O(1) bond lengths are 2.11 Å. Both Mg(1)-O(2) bond lengths are 2.12 Å. Both Mg(1)-O(3) bond lengths are 2.08 Å. In the second Mg site, Mg(2) is bonded to one O(1), two equivalent O(2), and three equivalent O(3) atoms to form MgO6 octahedra that share  a cornercorner with one Mg(1)O6 octahedra, corners with two equivalent Fe(1)O6 octahedra, corners with three equivalent Mg(2)O6 octahedra, edges with three equivalent Mg(1)O6 octahedra, edges with three equivalent Mg(2)O6 octahedra, and edges with six equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-9°. The Mg(2)-O(1) bond length is 2.12 Å. There is one shorter (2.04 Å) and one longer (2.13 Å) Mg(2)-O(2) bond length. There are a spread of Mg(2)-O(3) bond distances ranging from 2.09-2.11 Å. Fe(1) is bonded to one O(1), two equivalent O(3), and three equivalent O(2) atoms to form FeO6 octahedra that share  a cornercorner with one Mg(1)O6 octahedra, corners with two equivalent Mg(2)O6 octahedra, corners with three equivalent Fe(1)O6 octahedra, edges with three equivalent Mg(1)O6 octahedra, edges with three equivalent Fe(1)O6 octahedra, and edges with six equivalent Mg(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-12°. The Fe(1)-O(1) bond length is 2.14 Å. There is one shorter (2.11 Å) and one longer (2.31 Å) Fe(1)-O(3) bond length. There are a spread of Fe(1)-O(2) bond distances ranging from 2.06-2.17 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Mg(1), two equivalent Mg(2), and two equivalent Fe(1) atoms to form OMg4Fe2 octahedra that share corners with two equivalent O(2)Mg3Fe3 octahedra, corners with two equivalent O(1)Mg4Fe2 octahedra, corners with two equivalent O(3)Mg4Fe2 octahedra, edges with six equivalent O(2)Mg3Fe3 octahedra, and edges with six equivalent O(3)Mg4Fe2 octahedra. The corner-sharing octahedral tilt angles range from 0-11°. In the second O site, O(2) is bonded to one Mg(1), two equivalent Mg(2), and three equivalent Fe(1) atoms to form OMg3Fe3 octahedra that share  a cornercorner with one O(1)Mg4Fe2 octahedra, corners with two equivalent O(3)Mg4Fe2 octahedra, corners with three equivalent O(2)Mg3Fe3 octahedra, edges with three equivalent O(2)Mg3Fe3 octahedra, edges with three equivalent O(1)Mg4Fe2 octahedra, and edges with six equivalent O(3)Mg4Fe2 octahedra. The corner-sharing octahedral tilt angles range from 0-12°. In the third O site, O(3) is bonded to one Mg(1), three equivalent Mg(2), and two equivalent Fe(1) atoms to form OMg4Fe2 octahedra that share  a cornercorner with one O(1)Mg4Fe2 octahedra, corners with two equivalent O(2)Mg3Fe3 octahedra, corners with three equivalent O(3)Mg4Fe2 octahedra, edges with three equivalent O(1)Mg4Fe2 octahedra, edges with three equivalent O(3)Mg4Fe2 octahedra, and edges with six equivalent O(2)Mg3Fe3 octahedra. The corner-sharing octahedral tilt angles range from 0-11°.