MgFe2(SeO5)2 crystallizes in the monoclinic C2 space group. Mg(1) is bonded in a 7-coordinate geometry to one O(5), two equivalent O(1), two equivalent O(3), and two equivalent O(4) atoms. Fe(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form FeO6 octahedra that share corners with two equivalent Fe(1)O6 octahedra, corners with two equivalent Se(1)O4 tetrahedra, and corners with two equivalent Se(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 37-43°. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded to two equivalent O(1) and two equivalent O(3) atoms to form SeO4 tetrahedra that share corners with four equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 48-57°. In the second Se site, Se(2) is bonded to two equivalent O(2) and two equivalent O(4) atoms to form SeO4 tetrahedra that share corners with four equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 40-49°. There are six inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal non-coplanar geometry to one Mg(1), one Fe(1), and one Se(1) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Fe(1) and one Se(2) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Mg(1), one Fe(1), and one Se(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Mg(1), one Fe(1), and one Se(2) atom. In the fifth O site, O(5) is bonded in a trigonal planar geometry to one Mg(1) and two equivalent Fe(1) atoms. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to two equivalent Fe(1) atoms.
MgFe2(SeO5)2 crystallizes in the monoclinic C2 space group. Mg(1) is bonded in a 7-coordinate geometry to one O(5), two equivalent O(1), two equivalent O(3), and two equivalent O(4) atoms. The Mg(1)-O(5) bond length is 1.97 Å. Both Mg(1)-O(1) bond lengths are 2.31 Å. Both Mg(1)-O(3) bond lengths are 2.53 Å. Both Mg(1)-O(4) bond lengths are 2.27 Å. Fe(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form FeO6 octahedra that share corners with two equivalent Fe(1)O6 octahedra, corners with two equivalent Se(1)O4 tetrahedra, and corners with two equivalent Se(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 37-43°. The Fe(1)-O(1) bond length is 2.26 Å. The Fe(1)-O(2) bond length is 2.06 Å. The Fe(1)-O(3) bond length is 2.19 Å. The Fe(1)-O(4) bond length is 2.16 Å. The Fe(1)-O(5) bond length is 1.91 Å. The Fe(1)-O(6) bond length is 1.83 Å. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded to two equivalent O(1) and two equivalent O(3) atoms to form SeO4 tetrahedra that share corners with four equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 48-57°. Both Se(1)-O(1) bond lengths are 1.69 Å. Both Se(1)-O(3) bond lengths are 1.68 Å. In the second Se site, Se(2) is bonded to two equivalent O(2) and two equivalent O(4) atoms to form SeO4 tetrahedra that share corners with four equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 40-49°. Both Se(2)-O(2) bond lengths are 1.66 Å. Both Se(2)-O(4) bond lengths are 1.70 Å. There are six inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal non-coplanar geometry to one Mg(1), one Fe(1), and one Se(1) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Fe(1) and one Se(2) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Mg(1), one Fe(1), and one Se(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Mg(1), one Fe(1), and one Se(2) atom. In the fifth O site, O(5) is bonded in a trigonal planar geometry to one Mg(1) and two equivalent Fe(1) atoms. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to two equivalent Fe(1) atoms.