MgFe4O9 crystallizes in the tetragonal P4/n space group. Mg(1) is bonded in a 8-coordinate geometry to four equivalent O(2) and four equivalent O(3) atoms. Fe(1) is bonded to one O(1), one O(2), and three equivalent O(3) atoms to form a mixture of distorted corner and edge-sharing FeO5 trigonal bipyramids. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted square co-planar geometry to four equivalent Fe(1) atoms. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one Mg(1) and one Fe(1) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Mg(1) and three equivalent Fe(1) atoms.
MgFe4O9 crystallizes in the tetragonal P4/n space group. Mg(1) is bonded in a 8-coordinate geometry to four equivalent O(2) and four equivalent O(3) atoms. All Mg(1)-O(2) bond lengths are 2.13 Å. All Mg(1)-O(3) bond lengths are 2.42 Å. Fe(1) is bonded to one O(1), one O(2), and three equivalent O(3) atoms to form a mixture of distorted corner and edge-sharing FeO5 trigonal bipyramids. The Fe(1)-O(1) bond length is 2.00 Å. The Fe(1)-O(2) bond length is 1.67 Å. There are a spread of Fe(1)-O(3) bond distances ranging from 1.87-1.97 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted square co-planar geometry to four equivalent Fe(1) atoms. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one Mg(1) and one Fe(1) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Mg(1) and three equivalent Fe(1) atoms.