MgMn2O4 is Spinel-like structured and crystallizes in the monoclinic Cm space group. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one O(11), one O(4), and two equivalent O(9) atoms to form MgO4 tetrahedra that share  a cornercorner with one Mn(6)O6 octahedra, corners with two equivalent Mn(4)O6 octahedra, corners with two equivalent Mn(5)O6 octahedra, corners with three equivalent Mg(4)O6 octahedra, and corners with four equivalent Mn(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 50-63°. In the second Mg site, Mg(2) is bonded to one O(12), one O(3), and two equivalent O(10) atoms to form MgO4 tetrahedra that share  a cornercorner with one Mn(5)O6 octahedra, corners with two equivalent Mn(3)O6 octahedra, corners with two equivalent Mn(6)O6 octahedra, corners with three equivalent Mg(3)O6 octahedra, and corners with four equivalent Mn(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 50-63°. In the third Mg site, Mg(3) is bonded to one O(12), one O(7), two equivalent O(10), and two equivalent O(5) atoms to form MgO6 octahedra that share corners with three equivalent Mg(2)O4 tetrahedra, corners with three equivalent Mn(2)O4 tetrahedra,  an edgeedge with one Mn(5)O6 octahedra,  an edgeedge with one Mn(6)O6 octahedra, edges with two equivalent Mn(3)O6 octahedra, and edges with two equivalent Mn(4)O6 octahedra. In the fourth Mg site, Mg(4) is bonded to one O(11), one O(8), two equivalent O(6), and two equivalent O(9) atoms to form MgO6 octahedra that share corners with three equivalent Mg(1)O4 tetrahedra, corners with three equivalent Mn(1)O4 tetrahedra,  an edgeedge with one Mn(5)O6 octahedra,  an edgeedge with one Mn(6)O6 octahedra, edges with two equivalent Mn(3)O6 octahedra, and edges with two equivalent Mn(4)O6 octahedra. There are six inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to one O(1), one O(8), and two equivalent O(6) atoms to form MnO4 tetrahedra that share  a cornercorner with one Mn(5)O6 octahedra, corners with two equivalent Mn(3)O6 octahedra, corners with two equivalent Mn(6)O6 octahedra, corners with three equivalent Mg(4)O6 octahedra, and corners with four equivalent Mn(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 51-65°. In the second Mn site, Mn(2) is bonded to one O(2), one O(7), and two equivalent O(5) atoms to form MnO4 tetrahedra that share  a cornercorner with one Mn(6)O6 octahedra, corners with two equivalent Mn(4)O6 octahedra, corners with two equivalent Mn(5)O6 octahedra, corners with three equivalent Mg(3)O6 octahedra, and corners with four equivalent Mn(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 50-63°. In the third Mn site, Mn(3) is bonded to one O(1), one O(11), one O(3), one O(5), one O(7), and one O(9) atom to form MnO6 octahedra that share  a cornercorner with one Mg(2)O4 tetrahedra,  a cornercorner with one Mn(1)O4 tetrahedra, corners with two equivalent Mg(1)O4 tetrahedra, corners with two equivalent Mn(2)O4 tetrahedra,  an edgeedge with one Mg(3)O6 octahedra,  an edgeedge with one Mg(4)O6 octahedra, edges with two equivalent Mn(3)O6 octahedra, and edges with two equivalent Mn(5)O6 octahedra. In the fourth Mn site, Mn(4) is bonded to one O(10), one O(12), one O(2), one O(4), one O(6), and one O(8) atom to form MnO6 octahedra that share  a cornercorner with one Mg(1)O4 tetrahedra,  a cornercorner with one Mn(2)O4 tetrahedra, corners with two equivalent Mg(2)O4 tetrahedra, corners with two equivalent Mn(1)O4 tetrahedra,  an edgeedge with one Mg(3)O6 octahedra,  an edgeedge with one Mg(4)O6 octahedra, edges with two equivalent Mn(4)O6 octahedra, and edges with two equivalent Mn(6)O6 octahedra. In the fifth Mn site, Mn(5) is bonded to one O(1), one O(3), two equivalent O(5), and two equivalent O(9) atoms to form MnO6 octahedra that share  a cornercorner with one Mg(2)O4 tetrahedra,  a cornercorner with one Mn(1)O4 tetrahedra, corners with two equivalent Mg(1)O4 tetrahedra, corners with two equivalent Mn(2)O4 tetrahedra,  an edgeedge with one Mg(3)O6 octahedra,  an edgeedge with one Mg(4)O6 octahedra, and edges with four equivalent Mn(3)O6 octahedra. In the sixth Mn site, Mn(6) is bonded to one O(2), one O(4), two equivalent O(10), and two equivalent O(6) atoms to form MnO6 octahedra that share  a cornercorner with one Mg(1)O4 tetrahedra,  a cornercorner with one Mn(2)O4 tetrahedra, corners with two equivalent Mg(2)O4 tetrahedra, corners with two equivalent Mn(1)O4 tetrahedra,  an edgeedge with one Mg(3)O6 octahedra,  an edgeedge with one Mg(4)O6 octahedra, and edges with four equivalent Mn(4)O6 octahedra. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Mn(1), one Mn(5), and two equivalent Mn(3) atoms. In the second O site, O(2) is bonded in a rectangular see-saw-like geometry to one Mn(2), one Mn(6), and two equivalent Mn(4) atoms. In the third O site, O(3) is bonded in a rectangular see-saw-like geometry to one Mg(2), one Mn(5), and two equivalent Mn(3) atoms. In the fourth O site, O(4) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Mn(6), and two equivalent Mn(4) atoms. In the fifth O site, O(5) is bonded to one Mg(3), one Mn(2), one Mn(3), and one Mn(5) atom to form distorted OMgMn3 trigonal pyramids that share  a cornercorner with one O(7)MgMn3 tetrahedra,  a cornercorner with one O(11)Mg2Mn2 trigonal pyramid,  a cornercorner with one O(12)Mg2Mn2 trigonal pyramid,  a cornercorner with one O(5)MgMn3 trigonal pyramid, corners with two equivalent O(10)Mg2Mn2 trigonal pyramids, corners with three equivalent O(9)Mg2Mn2 trigonal pyramids,  an edgeedge with one O(7)MgMn3 tetrahedra, and  an edgeedge with one O(5)MgMn3 trigonal pyramid. In the sixth O site, O(6) is bonded to one Mg(4), one Mn(1), one Mn(4), and one Mn(6) atom to form distorted OMgMn3 trigonal pyramids that share  a cornercorner with one O(8)MgMn3 tetrahedra,  a cornercorner with one O(11)Mg2Mn2 trigonal pyramid,  a cornercorner with one O(12)Mg2Mn2 trigonal pyramid,  a cornercorner with one O(6)MgMn3 trigonal pyramid, corners with two equivalent O(9)Mg2Mn2 trigonal pyramids, corners with three equivalent O(10)Mg2Mn2 trigonal pyramids,  an edgeedge with one O(8)MgMn3 tetrahedra, and  an edgeedge with one O(6)MgMn3 trigonal pyramid. In the seventh O site, O(7) is bonded to one Mg(3), one Mn(2), and two equivalent Mn(3) atoms to form distorted OMgMn3 tetrahedra that share  a cornercorner with one O(12)Mg2Mn2 trigonal pyramid, corners with two equivalent O(10)Mg2Mn2 trigonal pyramids, corners with two equivalent O(11)Mg2Mn2 trigonal pyramids, corners with two equivalent O(9)Mg2Mn2 trigonal pyramids, corners with two equivalent O(5)MgMn3 trigonal pyramids, and edges with two equivalent O(5)MgMn3 trigonal pyramids. In the eighth O site, O(8) is bonded to one Mg(4), one Mn(1), and two equivalent Mn(4) atoms to form OMgMn3 tetrahedra that share  a cornercorner with one O(11)Mg2Mn2 trigonal pyramid, corners with two equivalent O(10)Mg2Mn2 trigonal pyramids, corners with two equivalent O(12)Mg2Mn2 trigonal pyramids, corners with two equivalent O(9)Mg2Mn2 trigonal pyramids, corners with two equivalent O(6)MgMn3 trigonal pyramids, and edges with two equivalent O(6)MgMn3 trigonal pyramids. In the ninth O site, O(9) is bonded to one Mg(1), one Mg(4), one Mn(3), and one Mn(5) atom to form distorted OMg2Mn2 trigonal pyramids that share  a cornercorner with one O(7)MgMn3 tetrahedra,  a cornercorner with one O(8)MgMn3 tetrahedra,  a cornercorner with one O(11)Mg2Mn2 trigonal pyramid,  a cornercorner with one O(9)Mg2Mn2 trigonal pyramid, corners with two equivalent O(6)MgMn3 trigonal pyramids, corners with three equivalent O(5)MgMn3 trigonal pyramids,  an edgeedge with one O(11)Mg2Mn2 trigonal pyramid, and  an edgeedge with one O(9)Mg2Mn2 trigonal pyramid. In the tenth O site, O(10) is bonded to one Mg(2), one Mg(3), one Mn(4), and one Mn(6) atom to form distorted OMg2Mn2 trigonal pyramids that share  a cornercorner with one O(7)MgMn3 tetrahedra,  a cornercorner with one O(8)MgMn3 tetrahedra,  a cornercorner with one O(10)Mg2Mn2 trigonal pyramid,  a cornercorner with one O(12)Mg2Mn2 trigonal pyramid, corners with two equivalent O(5)MgMn3 trigonal pyramids, corners with three equivalent O(6)MgMn3 trigonal pyramids,  an edgeedge with one O(10)Mg2Mn2 trigonal pyramid, and  an edgeedge with one O(12)Mg2Mn2 trigonal pyramid. In the eleventh O site, O(11) is bonded to one Mg(1), one Mg(4), and two equivalent Mn(3) atoms to form distorted OMg2Mn2 trigonal pyramids that share  a cornercorner with one O(8)MgMn3 tetrahedra, corners with two equivalent O(7)MgMn3 tetrahedra, corners with two equivalent O(9)Mg2Mn2 trigonal pyramids, corners with two equivalent O(5)MgMn3 trigonal pyramids, corners with two equivalent O(6)MgMn3 trigonal pyramids, and edges with two equivalent O(9)Mg2Mn2 trigonal pyramids. In the twelfth O site, O(12) is bonded to one Mg(2), one Mg(3), and two equivalent Mn(4) atoms to form distorted OMg2Mn2 trigonal pyramids that share  a cornercorner with one O(7)MgMn3 tetrahedra, corners with two equivalent O(8)MgMn3 tetrahedra, corners with two equivalent O(10)Mg2Mn2 trigonal pyramids, corners with two equivalent O(5)MgMn3 trigonal pyramids, corners with two equivalent O(6)MgMn3 trigonal pyramids, and edges with two equivalent O(10)Mg2Mn2 trigonal pyramids.
MgMn2O4 is Spinel-like structured and crystallizes in the monoclinic Cm space group. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one O(11), one O(4), and two equivalent O(9) atoms to form MgO4 tetrahedra that share  a cornercorner with one Mn(6)O6 octahedra, corners with two equivalent Mn(4)O6 octahedra, corners with two equivalent Mn(5)O6 octahedra, corners with three equivalent Mg(4)O6 octahedra, and corners with four equivalent Mn(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 50-63°. The Mg(1)-O(11) bond length is 2.00 Å. The Mg(1)-O(4) bond length is 1.99 Å. Both Mg(1)-O(9) bond lengths are 2.04 Å. In the second Mg site, Mg(2) is bonded to one O(12), one O(3), and two equivalent O(10) atoms to form MgO4 tetrahedra that share  a cornercorner with one Mn(5)O6 octahedra, corners with two equivalent Mn(3)O6 octahedra, corners with two equivalent Mn(6)O6 octahedra, corners with three equivalent Mg(3)O6 octahedra, and corners with four equivalent Mn(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 50-63°. The Mg(2)-O(12) bond length is 2.00 Å. The Mg(2)-O(3) bond length is 1.99 Å. Both Mg(2)-O(10) bond lengths are 2.04 Å. In the third Mg site, Mg(3) is bonded to one O(12), one O(7), two equivalent O(10), and two equivalent O(5) atoms to form MgO6 octahedra that share corners with three equivalent Mg(2)O4 tetrahedra, corners with three equivalent Mn(2)O4 tetrahedra,  an edgeedge with one Mn(5)O6 octahedra,  an edgeedge with one Mn(6)O6 octahedra, edges with two equivalent Mn(3)O6 octahedra, and edges with two equivalent Mn(4)O6 octahedra. The Mg(3)-O(12) bond length is 2.08 Å. The Mg(3)-O(7) bond length is 2.08 Å. Both Mg(3)-O(10) bond lengths are 2.11 Å. Both Mg(3)-O(5) bond lengths are 2.11 Å. In the fourth Mg site, Mg(4) is bonded to one O(11), one O(8), two equivalent O(6), and two equivalent O(9) atoms to form MgO6 octahedra that share corners with three equivalent Mg(1)O4 tetrahedra, corners with three equivalent Mn(1)O4 tetrahedra,  an edgeedge with one Mn(5)O6 octahedra,  an edgeedge with one Mn(6)O6 octahedra, edges with two equivalent Mn(3)O6 octahedra, and edges with two equivalent Mn(4)O6 octahedra. The Mg(4)-O(11) bond length is 2.08 Å. The Mg(4)-O(8) bond length is 2.07 Å. Both Mg(4)-O(6) bond lengths are 2.11 Å. Both Mg(4)-O(9) bond lengths are 2.11 Å. There are six inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to one O(1), one O(8), and two equivalent O(6) atoms to form MnO4 tetrahedra that share  a cornercorner with one Mn(5)O6 octahedra, corners with two equivalent Mn(3)O6 octahedra, corners with two equivalent Mn(6)O6 octahedra, corners with three equivalent Mg(4)O6 octahedra, and corners with four equivalent Mn(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 51-65°. The Mn(1)-O(1) bond length is 2.03 Å. The Mn(1)-O(8) bond length is 2.05 Å. Both Mn(1)-O(6) bond lengths are 2.08 Å. In the second Mn site, Mn(2) is bonded to one O(2), one O(7), and two equivalent O(5) atoms to form MnO4 tetrahedra that share  a cornercorner with one Mn(6)O6 octahedra, corners with two equivalent Mn(4)O6 octahedra, corners with two equivalent Mn(5)O6 octahedra, corners with three equivalent Mg(3)O6 octahedra, and corners with four equivalent Mn(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 50-63°. The Mn(2)-O(2) bond length is 2.02 Å. The Mn(2)-O(7) bond length is 2.04 Å. Both Mn(2)-O(5) bond lengths are 2.06 Å. In the third Mn site, Mn(3) is bonded to one O(1), one O(11), one O(3), one O(5), one O(7), and one O(9) atom to form MnO6 octahedra that share  a cornercorner with one Mg(2)O4 tetrahedra,  a cornercorner with one Mn(1)O4 tetrahedra, corners with two equivalent Mg(1)O4 tetrahedra, corners with two equivalent Mn(2)O4 tetrahedra,  an edgeedge with one Mg(3)O6 octahedra,  an edgeedge with one Mg(4)O6 octahedra, edges with two equivalent Mn(3)O6 octahedra, and edges with two equivalent Mn(5)O6 octahedra. The Mn(3)-O(1) bond length is 2.19 Å. The Mn(3)-O(11) bond length is 1.97 Å. The Mn(3)-O(3) bond length is 2.22 Å. The Mn(3)-O(5) bond length is 2.01 Å. The Mn(3)-O(7) bond length is 1.96 Å. The Mn(3)-O(9) bond length is 2.01 Å. In the fourth Mn site, Mn(4) is bonded to one O(10), one O(12), one O(2), one O(4), one O(6), and one O(8) atom to form MnO6 octahedra that share  a cornercorner with one Mg(1)O4 tetrahedra,  a cornercorner with one Mn(2)O4 tetrahedra, corners with two equivalent Mg(2)O4 tetrahedra, corners with two equivalent Mn(1)O4 tetrahedra,  an edgeedge with one Mg(3)O6 octahedra,  an edgeedge with one Mg(4)O6 octahedra, edges with two equivalent Mn(4)O6 octahedra, and edges with two equivalent Mn(6)O6 octahedra. The Mn(4)-O(10) bond length is 2.00 Å. The Mn(4)-O(12) bond length is 1.96 Å. The Mn(4)-O(2) bond length is 2.21 Å. The Mn(4)-O(4) bond length is 2.22 Å. The Mn(4)-O(6) bond length is 1.99 Å. The Mn(4)-O(8) bond length is 1.95 Å. In the fifth Mn site, Mn(5) is bonded to one O(1), one O(3), two equivalent O(5), and two equivalent O(9) atoms to form MnO6 octahedra that share  a cornercorner with one Mg(2)O4 tetrahedra,  a cornercorner with one Mn(1)O4 tetrahedra, corners with two equivalent Mg(1)O4 tetrahedra, corners with two equivalent Mn(2)O4 tetrahedra,  an edgeedge with one Mg(3)O6 octahedra,  an edgeedge with one Mg(4)O6 octahedra, and edges with four equivalent Mn(3)O6 octahedra. The Mn(5)-O(1) bond length is 1.92 Å. The Mn(5)-O(3) bond length is 1.94 Å. Both Mn(5)-O(5) bond lengths are 1.98 Å. Both Mn(5)-O(9) bond lengths are 1.99 Å. In the sixth Mn site, Mn(6) is bonded to one O(2), one O(4), two equivalent O(10), and two equivalent O(6) atoms to form MnO6 octahedra that share  a cornercorner with one Mg(1)O4 tetrahedra,  a cornercorner with one Mn(2)O4 tetrahedra, corners with two equivalent Mg(2)O4 tetrahedra, corners with two equivalent Mn(1)O4 tetrahedra,  an edgeedge with one Mg(3)O6 octahedra,  an edgeedge with one Mg(4)O6 octahedra, and edges with four equivalent Mn(4)O6 octahedra. The Mn(6)-O(2) bond length is 1.94 Å. The Mn(6)-O(4) bond length is 1.94 Å. Both Mn(6)-O(10) bond lengths are 1.99 Å. Both Mn(6)-O(6) bond lengths are 1.96 Å. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Mn(1), one Mn(5), and two equivalent Mn(3) atoms. In the second O site, O(2) is bonded in a rectangular see-saw-like geometry to one Mn(2), one Mn(6), and two equivalent Mn(4) atoms. In the third O site, O(3) is bonded in a rectangular see-saw-like geometry to one Mg(2), one Mn(5), and two equivalent Mn(3) atoms. In the fourth O site, O(4) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Mn(6), and two equivalent Mn(4) atoms. In the fifth O site, O(5) is bonded to one Mg(3), one Mn(2), one Mn(3), and one Mn(5) atom to form distorted OMgMn3 trigonal pyramids that share  a cornercorner with one O(7)MgMn3 tetrahedra,  a cornercorner with one O(11)Mg2Mn2 trigonal pyramid,  a cornercorner with one O(12)Mg2Mn2 trigonal pyramid,  a cornercorner with one O(5)MgMn3 trigonal pyramid, corners with two equivalent O(10)Mg2Mn2 trigonal pyramids, corners with three equivalent O(9)Mg2Mn2 trigonal pyramids,  an edgeedge with one O(7)MgMn3 tetrahedra, and  an edgeedge with one O(5)MgMn3 trigonal pyramid. In the sixth O site, O(6) is bonded to one Mg(4), one Mn(1), one Mn(4), and one Mn(6) atom to form distorted OMgMn3 trigonal pyramids that share  a cornercorner with one O(8)MgMn3 tetrahedra,  a cornercorner with one O(11)Mg2Mn2 trigonal pyramid,  a cornercorner with one O(12)Mg2Mn2 trigonal pyramid,  a cornercorner with one O(6)MgMn3 trigonal pyramid, corners with two equivalent O(9)Mg2Mn2 trigonal pyramids, corners with three equivalent O(10)Mg2Mn2 trigonal pyramids,  an edgeedge with one O(8)MgMn3 tetrahedra, and  an edgeedge with one O(6)MgMn3 trigonal pyramid. In the seventh O site, O(7) is bonded to one Mg(3), one Mn(2), and two equivalent Mn(3) atoms to form distorted OMgMn3 tetrahedra that share  a cornercorner with one O(12)Mg2Mn2 trigonal pyramid, corners with two equivalent O(10)Mg2Mn2 trigonal pyramids, corners with two equivalent O(11)Mg2Mn2 trigonal pyramids, corners with two equivalent O(9)Mg2Mn2 trigonal pyramids, corners with two equivalent O(5)MgMn3 trigonal pyramids, and edges with two equivalent O(5)MgMn3 trigonal pyramids. In the eighth O site, O(8) is bonded to one Mg(4), one Mn(1), and two equivalent Mn(4) atoms to form OMgMn3 tetrahedra that share  a cornercorner with one O(11)Mg2Mn2 trigonal pyramid, corners with two equivalent O(10)Mg2Mn2 trigonal pyramids, corners with two equivalent O(12)Mg2Mn2 trigonal pyramids, corners with two equivalent O(9)Mg2Mn2 trigonal pyramids, corners with two equivalent O(6)MgMn3 trigonal pyramids, and edges with two equivalent O(6)MgMn3 trigonal pyramids. In the ninth O site, O(9) is bonded to one Mg(1), one Mg(4), one Mn(3), and one Mn(5) atom to form distorted OMg2Mn2 trigonal pyramids that share  a cornercorner with one O(7)MgMn3 tetrahedra,  a cornercorner with one O(8)MgMn3 tetrahedra,  a cornercorner with one O(11)Mg2Mn2 trigonal pyramid,  a cornercorner with one O(9)Mg2Mn2 trigonal pyramid, corners with two equivalent O(6)MgMn3 trigonal pyramids, corners with three equivalent O(5)MgMn3 trigonal pyramids,  an edgeedge with one O(11)Mg2Mn2 trigonal pyramid, and  an edgeedge with one O(9)Mg2Mn2 trigonal pyramid. In the tenth O site, O(10) is bonded to one Mg(2), one Mg(3), one Mn(4), and one Mn(6) atom to form distorted OMg2Mn2 trigonal pyramids that share  a cornercorner with one O(7)MgMn3 tetrahedra,  a cornercorner with one O(8)MgMn3 tetrahedra,  a cornercorner with one O(10)Mg2Mn2 trigonal pyramid,  a cornercorner with one O(12)Mg2Mn2 trigonal pyramid, corners with two equivalent O(5)MgMn3 trigonal pyramids, corners with three equivalent O(6)MgMn3 trigonal pyramids,  an edgeedge with one O(10)Mg2Mn2 trigonal pyramid, and  an edgeedge with one O(12)Mg2Mn2 trigonal pyramid. In the eleventh O site, O(11) is bonded to one Mg(1), one Mg(4), and two equivalent Mn(3) atoms to form distorted OMg2Mn2 trigonal pyramids that share  a cornercorner with one O(8)MgMn3 tetrahedra, corners with two equivalent O(7)MgMn3 tetrahedra, corners with two equivalent O(9)Mg2Mn2 trigonal pyramids, corners with two equivalent O(5)MgMn3 trigonal pyramids, corners with two equivalent O(6)MgMn3 trigonal pyramids, and edges with two equivalent O(9)Mg2Mn2 trigonal pyramids. In the twelfth O site, O(12) is bonded to one Mg(2), one Mg(3), and two equivalent Mn(4) atoms to form distorted OMg2Mn2 trigonal pyramids that share  a cornercorner with one O(7)MgMn3 tetrahedra, corners with two equivalent O(8)MgMn3 tetrahedra, corners with two equivalent O(10)Mg2Mn2 trigonal pyramids, corners with two equivalent O(5)MgMn3 trigonal pyramids, corners with two equivalent O(6)MgMn3 trigonal pyramids, and edges with two equivalent O(10)Mg2Mn2 trigonal pyramids.