MgMn5O8 crystallizes in the triclinic P-1 space group. 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 six equivalent Mn(5)O6 octahedra, edges with two equivalent Mn(1)O6 octahedra, edges with two equivalent Mn(2)O6 octahedra, edges with two equivalent Mn(3)O6 octahedra, and edges with two equivalent Mn(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 11-16°. There are five inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form MnO6 octahedra that share corners with six equivalent Mn(2)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Mn(3)O6 octahedra, edges with two equivalent Mn(4)O6 octahedra, and edges with two equivalent Mn(5)O6 octahedra. The corner-sharing octahedral tilt angles range from 12-16°. In the second Mn site, Mn(2) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form MnO6 octahedra that share corners with six equivalent Mn(1)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Mn(3)O6 octahedra, edges with two equivalent Mn(4)O6 octahedra, and edges with two equivalent Mn(5)O6 octahedra. The corner-sharing octahedral tilt angles range from 12-16°. In the third Mn site, Mn(3) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(4) atoms to form MnO6 octahedra that share edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Mn(1)O6 octahedra, edges with two equivalent Mn(2)O6 octahedra, edges with two equivalent Mn(4)O6 octahedra, and edges with two equivalent Mn(5)O6 octahedra. In the fourth Mn site, Mn(4) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms to form MnO6 octahedra that share edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Mn(1)O6 octahedra, edges with two equivalent Mn(2)O6 octahedra, edges with two equivalent Mn(3)O6 octahedra, and edges with two equivalent Mn(5)O6 octahedra. In the fifth Mn site, Mn(5) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form MnO6 octahedra that share corners with six equivalent Mg(1)O6 octahedra, edges with two equivalent Mn(1)O6 octahedra, edges with two equivalent Mn(2)O6 octahedra, edges with two equivalent Mn(3)O6 octahedra, and edges with two equivalent Mn(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 11-16°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a see-saw-like geometry to one Mg(1), one Mn(3), one Mn(4), and one Mn(5) atom. In the second O site, O(2) is bonded to one Mg(1), one Mn(1), one Mn(2), one Mn(4), and one Mn(5) atom to form a mixture of corner and edge-sharing OMgMn4 square pyramids. In the third O site, O(3) is bonded to one Mg(1), one Mn(1), one Mn(2), one Mn(3), and one Mn(5) atom to form a mixture of corner and edge-sharing OMgMn4 square pyramids. In the fourth O site, O(4) is bonded in a see-saw-like geometry to one Mn(1), one Mn(2), one Mn(3), and one Mn(4) atom.
MgMn5O8 crystallizes in the triclinic P-1 space group. 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 six equivalent Mn(5)O6 octahedra, edges with two equivalent Mn(1)O6 octahedra, edges with two equivalent Mn(2)O6 octahedra, edges with two equivalent Mn(3)O6 octahedra, and edges with two equivalent Mn(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 11-16°. Both Mg(1)-O(1) bond lengths are 2.15 Å. Both Mg(1)-O(2) bond lengths are 2.15 Å. Both Mg(1)-O(3) bond lengths are 2.15 Å. There are five inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form MnO6 octahedra that share corners with six equivalent Mn(2)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Mn(3)O6 octahedra, edges with two equivalent Mn(4)O6 octahedra, and edges with two equivalent Mn(5)O6 octahedra. The corner-sharing octahedral tilt angles range from 12-16°. Both Mn(1)-O(2) bond lengths are 2.19 Å. Both Mn(1)-O(3) bond lengths are 2.19 Å. Both Mn(1)-O(4) bond lengths are 2.17 Å. In the second Mn site, Mn(2) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form MnO6 octahedra that share corners with six equivalent Mn(1)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Mn(3)O6 octahedra, edges with two equivalent Mn(4)O6 octahedra, and edges with two equivalent Mn(5)O6 octahedra. The corner-sharing octahedral tilt angles range from 12-16°. Both Mn(2)-O(2) bond lengths are 2.21 Å. Both Mn(2)-O(3) bond lengths are 2.21 Å. Both Mn(2)-O(4) bond lengths are 2.19 Å. In the third Mn site, Mn(3) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(4) atoms to form MnO6 octahedra that share edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Mn(1)O6 octahedra, edges with two equivalent Mn(2)O6 octahedra, edges with two equivalent Mn(4)O6 octahedra, and edges with two equivalent Mn(5)O6 octahedra. Both Mn(3)-O(1) bond lengths are 1.99 Å. Both Mn(3)-O(3) bond lengths are 1.94 Å. Both Mn(3)-O(4) bond lengths are 2.00 Å. In the fourth Mn site, Mn(4) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms to form MnO6 octahedra that share edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Mn(1)O6 octahedra, edges with two equivalent Mn(2)O6 octahedra, edges with two equivalent Mn(3)O6 octahedra, and edges with two equivalent Mn(5)O6 octahedra. Both Mn(4)-O(1) bond lengths are 1.97 Å. Both Mn(4)-O(2) bond lengths are 1.94 Å. Both Mn(4)-O(4) bond lengths are 1.97 Å. In the fifth Mn site, Mn(5) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form MnO6 octahedra that share corners with six equivalent Mg(1)O6 octahedra, edges with two equivalent Mn(1)O6 octahedra, edges with two equivalent Mn(2)O6 octahedra, edges with two equivalent Mn(3)O6 octahedra, and edges with two equivalent Mn(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 11-16°. Both Mn(5)-O(1) bond lengths are 2.22 Å. Both Mn(5)-O(2) bond lengths are 2.25 Å. Both Mn(5)-O(3) bond lengths are 2.25 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a see-saw-like geometry to one Mg(1), one Mn(3), one Mn(4), and one Mn(5) atom. In the second O site, O(2) is bonded to one Mg(1), one Mn(1), one Mn(2), one Mn(4), and one Mn(5) atom to form a mixture of corner and edge-sharing OMgMn4 square pyramids. In the third O site, O(3) is bonded to one Mg(1), one Mn(1), one Mn(2), one Mn(3), and one Mn(5) atom to form a mixture of corner and edge-sharing OMgMn4 square pyramids. In the fourth O site, O(4) is bonded in a see-saw-like geometry to one Mn(1), one Mn(2), one Mn(3), and one Mn(4) atom.