MgFeF5 crystallizes in the monoclinic P2_1/c space group. Mg(1) is bonded in a 7-coordinate geometry to one F(3), one F(4), one F(5), two equivalent F(1), and two equivalent F(2) atoms. Fe(1) is bonded to one F(1), one F(2), one F(3), one F(4), and two equivalent F(5) atoms to form corner-sharing FeF6 octahedra. The corner-sharing octahedral tilt angles are 44°. There are five inequivalent F sites. In the first F site, F(1) is bonded in a distorted bent 150 degrees geometry to two equivalent Mg(1) and one Fe(1) atom. In the second F site, F(2) is bonded in a 3-coordinate geometry to two equivalent Mg(1) and one Fe(1) atom. In the third F site, F(3) is bonded in a bent 150 degrees geometry to one Mg(1) and one Fe(1) atom. In the fourth F site, F(4) is bonded in a linear geometry to one Mg(1) and one Fe(1) atom. In the fifth F site, F(5) is bonded in a trigonal planar geometry to one Mg(1) and two equivalent Fe(1) atoms.
MgFeF5 crystallizes in the monoclinic P2_1/c space group. Mg(1) is bonded in a 7-coordinate geometry to one F(3), one F(4), one F(5), two equivalent F(1), and two equivalent F(2) atoms. The Mg(1)-F(3) bond length is 1.94 Å. The Mg(1)-F(4) bond length is 1.95 Å. The Mg(1)-F(5) bond length is 2.24 Å. There is one shorter (2.02 Å) and one longer (2.60 Å) Mg(1)-F(1) bond length. There is one shorter (2.03 Å) and one longer (2.37 Å) Mg(1)-F(2) bond length. Fe(1) is bonded to one F(1), one F(2), one F(3), one F(4), and two equivalent F(5) atoms to form corner-sharing FeF6 octahedra. The corner-sharing octahedral tilt angles are 44°. The Fe(1)-F(1) bond length is 1.96 Å. The Fe(1)-F(2) bond length is 1.95 Å. The Fe(1)-F(3) bond length is 1.90 Å. The Fe(1)-F(4) bond length is 1.92 Å. There is one shorter (2.00 Å) and one longer (2.01 Å) Fe(1)-F(5) bond length. There are five inequivalent F sites. In the first F site, F(1) is bonded in a distorted bent 150 degrees geometry to two equivalent Mg(1) and one Fe(1) atom. In the second F site, F(2) is bonded in a 3-coordinate geometry to two equivalent Mg(1) and one Fe(1) atom. In the third F site, F(3) is bonded in a bent 150 degrees geometry to one Mg(1) and one Fe(1) atom. In the fourth F site, F(4) is bonded in a linear geometry to one Mg(1) and one Fe(1) atom. In the fifth F site, F(5) is bonded in a trigonal planar geometry to one Mg(1) and two equivalent Fe(1) atoms.