K2MgFe4O7 crystallizes in the monoclinic Cm space group. K(1) is bonded in a distorted trigonal planar geometry to three equivalent O(3) atoms. Mg(1) is bonded to one O(1), one O(2), two equivalent O(4), and two equivalent O(5) atoms to form MgO6 octahedra that share edges with six equivalent Fe(3)O6 octahedra. There are three inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a distorted rectangular see-saw-like geometry to one O(1), one O(3), and two equivalent O(4) atoms. In the second Fe site, Fe(2) is bonded in a distorted rectangular see-saw-like geometry to one O(2), one O(3), and two equivalent O(5) atoms. In the third Fe site, Fe(3) is bonded to one O(1), one O(2), two equivalent O(4), and two equivalent O(5) atoms to form FeO6 octahedra that share edges with three equivalent Mg(1)O6 octahedra and edges with three equivalent Fe(3)O6 octahedra. There are five inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Fe(1), and two equivalent Fe(3) atoms. In the second O site, O(2) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Fe(2), and two equivalent Fe(3) atoms. In the third O site, O(3) is bonded in a distorted linear geometry to six equivalent K(1), one Fe(1), and one Fe(2) atom. In the fourth O site, O(4) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Fe(1), and two equivalent Fe(3) atoms. In the fifth O site, O(5) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Fe(2), and two equivalent Fe(3) atoms.
K2MgFe4O7 crystallizes in the monoclinic Cm space group. K(1) is bonded in a distorted trigonal planar geometry to three equivalent O(3) atoms. There are a spread of K(1)-O(3) bond distances ranging from 3.00-3.06 Å. Mg(1) is bonded to one O(1), one O(2), two equivalent O(4), and two equivalent O(5) atoms to form MgO6 octahedra that share edges with six equivalent Fe(3)O6 octahedra. The Mg(1)-O(1) bond length is 2.11 Å. The Mg(1)-O(2) bond length is 2.10 Å. Both Mg(1)-O(4) bond lengths are 2.08 Å. Both Mg(1)-O(5) bond lengths are 2.08 Å. There are three inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a distorted rectangular see-saw-like geometry to one O(1), one O(3), and two equivalent O(4) atoms. The Fe(1)-O(1) bond length is 1.98 Å. The Fe(1)-O(3) bond length is 1.88 Å. Both Fe(1)-O(4) bond lengths are 2.16 Å. In the second Fe site, Fe(2) is bonded in a distorted rectangular see-saw-like geometry to one O(2), one O(3), and two equivalent O(5) atoms. The Fe(2)-O(2) bond length is 1.98 Å. The Fe(2)-O(3) bond length is 1.88 Å. Both Fe(2)-O(5) bond lengths are 2.15 Å. In the third Fe site, Fe(3) is bonded to one O(1), one O(2), two equivalent O(4), and two equivalent O(5) atoms to form FeO6 octahedra that share edges with three equivalent Mg(1)O6 octahedra and edges with three equivalent Fe(3)O6 octahedra. The Fe(3)-O(1) bond length is 2.11 Å. The Fe(3)-O(2) bond length is 2.11 Å. There is one shorter (2.07 Å) and one longer (2.10 Å) Fe(3)-O(4) bond length. There is one shorter (2.07 Å) and one longer (2.10 Å) Fe(3)-O(5) bond length. There are five inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Fe(1), and two equivalent Fe(3) atoms. In the second O site, O(2) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Fe(2), and two equivalent Fe(3) atoms. In the third O site, O(3) is bonded in a distorted linear geometry to six equivalent K(1), one Fe(1), and one Fe(2) atom. In the fourth O site, O(4) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Fe(1), and two equivalent Fe(3) atoms. In the fifth O site, O(5) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Fe(2), and two equivalent Fe(3) atoms.