MgMn4(FeO4)2 crystallizes in the tetragonal I-4m2 space group. Mg(1) is bonded in a 4-coordinate geometry to four equivalent O(1) atoms. Mn(1) is bonded in a 5-coordinate geometry to two equivalent O(1) and three equivalent O(2) atoms. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a tetrahedral geometry to four equivalent O(2) atoms. In the second Fe site, Fe(2) is bonded in a tetrahedral geometry to four equivalent O(1) atoms. There are two inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), two equivalent Mn(1), and one Fe(2) atom to form a mixture of distorted corner and face-sharing OMgMn2Fe tetrahedra. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to three equivalent Mn(1) and one Fe(1) atom.
MgMn4(FeO4)2 crystallizes in the tetragonal I-4m2 space group. Mg(1) is bonded in a 4-coordinate geometry to four equivalent O(1) atoms. All Mg(1)-O(1) bond lengths are 2.06 Å. Mn(1) is bonded in a 5-coordinate geometry to two equivalent O(1) and three equivalent O(2) atoms. Both Mn(1)-O(1) bond lengths are 2.15 Å. There is one shorter (2.14 Å) and two longer (2.22 Å) Mn(1)-O(2) bond lengths. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a tetrahedral geometry to four equivalent O(2) atoms. All Fe(1)-O(2) bond lengths are 2.01 Å. In the second Fe site, Fe(2) is bonded in a tetrahedral geometry to four equivalent O(1) atoms. All Fe(2)-O(1) bond lengths are 2.00 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), two equivalent Mn(1), and one Fe(2) atom to form a mixture of distorted corner and face-sharing OMgMn2Fe tetrahedra. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to three equivalent Mn(1) and one Fe(1) atom.