Mn4FeS5 is Caswellsilverite-like structured and crystallizes in the monoclinic C2/m space group. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to one S(2), two equivalent S(1), and three equivalent S(3) atoms to form MnS6 octahedra that share  a cornercorner with one Fe(1)S6 octahedra, corners with two equivalent Mn(1)S6 octahedra, corners with three equivalent Mn(2)S6 octahedra, edges with two equivalent Fe(1)S6 octahedra, edges with five equivalent Mn(1)S6 octahedra, and edges with five equivalent Mn(2)S6 octahedra. The corner-sharing octahedral tilt angles range from 0-2°. In the second Mn site, Mn(2) is bonded to one S(1), two equivalent S(3), and three equivalent S(2) atoms to form MnS6 octahedra that share  a cornercorner with one Mn(2)S6 octahedra, corners with two equivalent Fe(1)S6 octahedra, corners with three equivalent Mn(1)S6 octahedra, edges with three equivalent Fe(1)S6 octahedra, edges with four equivalent Mn(2)S6 octahedra, and edges with five equivalent Mn(1)S6 octahedra. The corner-sharing octahedral tilt angles range from 0-2°. Fe(1) is bonded to two equivalent S(3) and four equivalent S(2) atoms to form FeS6 octahedra that share corners with two equivalent Mn(1)S6 octahedra, corners with four equivalent Mn(2)S6 octahedra, edges with two equivalent Fe(1)S6 octahedra, edges with four equivalent Mn(1)S6 octahedra, and edges with six equivalent Mn(2)S6 octahedra. The corner-sharing octahedral tilt angles are 2°. There are three inequivalent S sites. In the first S site, S(1) is bonded to two equivalent Mn(2) and four equivalent Mn(1) atoms to form SMn6 octahedra that share corners with two equivalent S(2)Mn4Fe2 octahedra, corners with four equivalent S(3)Mn5Fe octahedra, edges with two equivalent S(1)Mn6 octahedra, edges with four equivalent S(2)Mn4Fe2 octahedra, and edges with six equivalent S(3)Mn5Fe octahedra. The corner-sharing octahedral tilt angles range from 1-2°. In the second S site, S(2) is bonded to one Mn(1), three equivalent Mn(2), and two equivalent Fe(1) atoms to form SMn4Fe2 octahedra that share  a cornercorner with one S(1)Mn6 octahedra, corners with two equivalent S(2)Mn4Fe2 octahedra, corners with three equivalent S(3)Mn5Fe octahedra, edges with two equivalent S(1)Mn6 octahedra, edges with five equivalent S(2)Mn4Fe2 octahedra, and edges with five equivalent S(3)Mn5Fe octahedra. The corner-sharing octahedral tilt angles range from 0-2°. In the third S site, S(3) is bonded to two equivalent Mn(2), three equivalent Mn(1), and one Fe(1) atom to form SMn5Fe octahedra that share  a cornercorner with one S(3)Mn5Fe octahedra, corners with two equivalent S(1)Mn6 octahedra, corners with three equivalent S(2)Mn4Fe2 octahedra, edges with three equivalent S(1)Mn6 octahedra, edges with four equivalent S(3)Mn5Fe octahedra, and edges with five equivalent S(2)Mn4Fe2 octahedra. The corner-sharing octahedral tilt angles range from 0-2°.
Mn4FeS5 is Caswellsilverite-like structured and crystallizes in the monoclinic C2/m space group. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to one S(2), two equivalent S(1), and three equivalent S(3) atoms to form MnS6 octahedra that share  a cornercorner with one Fe(1)S6 octahedra, corners with two equivalent Mn(1)S6 octahedra, corners with three equivalent Mn(2)S6 octahedra, edges with two equivalent Fe(1)S6 octahedra, edges with five equivalent Mn(1)S6 octahedra, and edges with five equivalent Mn(2)S6 octahedra. The corner-sharing octahedral tilt angles range from 0-2°. The Mn(1)-S(2) bond length is 2.49 Å. Both Mn(1)-S(1) bond lengths are 2.55 Å. All Mn(1)-S(3) bond lengths are 2.52 Å. In the second Mn site, Mn(2) is bonded to one S(1), two equivalent S(3), and three equivalent S(2) atoms to form MnS6 octahedra that share  a cornercorner with one Mn(2)S6 octahedra, corners with two equivalent Fe(1)S6 octahedra, corners with three equivalent Mn(1)S6 octahedra, edges with three equivalent Fe(1)S6 octahedra, edges with four equivalent Mn(2)S6 octahedra, and edges with five equivalent Mn(1)S6 octahedra. The corner-sharing octahedral tilt angles range from 0-2°. The Mn(2)-S(1) bond length is 2.54 Å. Both Mn(2)-S(3) bond lengths are 2.54 Å. There is one shorter (2.49 Å) and two longer (2.53 Å) Mn(2)-S(2) bond lengths. Fe(1) is bonded to two equivalent S(3) and four equivalent S(2) atoms to form FeS6 octahedra that share corners with two equivalent Mn(1)S6 octahedra, corners with four equivalent Mn(2)S6 octahedra, edges with two equivalent Fe(1)S6 octahedra, edges with four equivalent Mn(1)S6 octahedra, and edges with six equivalent Mn(2)S6 octahedra. The corner-sharing octahedral tilt angles are 2°. Both Fe(1)-S(3) bond lengths are 2.47 Å. All Fe(1)-S(2) bond lengths are 2.50 Å. There are three inequivalent S sites. In the first S site, S(1) is bonded to two equivalent Mn(2) and four equivalent Mn(1) atoms to form SMn6 octahedra that share corners with two equivalent S(2)Mn4Fe2 octahedra, corners with four equivalent S(3)Mn5Fe octahedra, edges with two equivalent S(1)Mn6 octahedra, edges with four equivalent S(2)Mn4Fe2 octahedra, and edges with six equivalent S(3)Mn5Fe octahedra. The corner-sharing octahedral tilt angles range from 1-2°. In the second S site, S(2) is bonded to one Mn(1), three equivalent Mn(2), and two equivalent Fe(1) atoms to form SMn4Fe2 octahedra that share  a cornercorner with one S(1)Mn6 octahedra, corners with two equivalent S(2)Mn4Fe2 octahedra, corners with three equivalent S(3)Mn5Fe octahedra, edges with two equivalent S(1)Mn6 octahedra, edges with five equivalent S(2)Mn4Fe2 octahedra, and edges with five equivalent S(3)Mn5Fe octahedra. The corner-sharing octahedral tilt angles range from 0-2°. In the third S site, S(3) is bonded to two equivalent Mn(2), three equivalent Mn(1), and one Fe(1) atom to form SMn5Fe octahedra that share  a cornercorner with one S(3)Mn5Fe octahedra, corners with two equivalent S(1)Mn6 octahedra, corners with three equivalent S(2)Mn4Fe2 octahedra, edges with three equivalent S(1)Mn6 octahedra, edges with four equivalent S(3)Mn5Fe octahedra, and edges with five equivalent S(2)Mn4Fe2 octahedra. The corner-sharing octahedral tilt angles range from 0-2°.