MgSbF5 crystallizes in the monoclinic P2_1/c space group. Mg(1) is bonded to one F(1), one F(3), one F(4), one F(5), and two equivalent F(2) atoms to form MgF6 octahedra that share corners with six equivalent Sb(1)F5 square pyramids and  an edgeedge with one Mg(1)F6 octahedra. Sb(1) is bonded to one F(1), one F(2), one F(3), one F(4), and one F(5) atom to form distorted SbF5 square pyramids that share corners with six equivalent Mg(1)F6 octahedra. The corner-sharing octahedral tilt angles range from 27-63°. There are five inequivalent F sites. In the first F site, F(1) is bonded in a bent 150 degrees geometry to one Mg(1) and one Sb(1) atom. In the second F site, F(2) is bonded in a distorted trigonal planar geometry to two equivalent Mg(1) and one Sb(1) atom. In the third F site, F(3) is bonded in a bent 150 degrees geometry to one Mg(1) and one Sb(1) atom. In the fourth F site, F(4) is bonded in a distorted bent 120 degrees geometry to one Mg(1) and one Sb(1) atom. In the fifth F site, F(5) is bonded in a bent 150 degrees geometry to one Mg(1) and one Sb(1) atom.
MgSbF5 crystallizes in the monoclinic P2_1/c space group. Mg(1) is bonded to one F(1), one F(3), one F(4), one F(5), and two equivalent F(2) atoms to form MgF6 octahedra that share corners with six equivalent Sb(1)F5 square pyramids and  an edgeedge with one Mg(1)F6 octahedra. The Mg(1)-F(1) bond length is 1.97 Å. The Mg(1)-F(3) bond length is 2.00 Å. The Mg(1)-F(4) bond length is 2.01 Å. The Mg(1)-F(5) bond length is 2.10 Å. Both Mg(1)-F(2) bond lengths are 2.05 Å. Sb(1) is bonded to one F(1), one F(2), one F(3), one F(4), and one F(5) atom to form distorted SbF5 square pyramids that share corners with six equivalent Mg(1)F6 octahedra. The corner-sharing octahedral tilt angles range from 27-63°. The Sb(1)-F(1) bond length is 2.12 Å. The Sb(1)-F(2) bond length is 2.32 Å. The Sb(1)-F(3) bond length is 2.04 Å. The Sb(1)-F(4) bond length is 2.23 Å. The Sb(1)-F(5) bond length is 2.04 Å. There are five inequivalent F sites. In the first F site, F(1) is bonded in a bent 150 degrees geometry to one Mg(1) and one Sb(1) atom. In the second F site, F(2) is bonded in a distorted trigonal planar geometry to two equivalent Mg(1) and one Sb(1) atom. In the third F site, F(3) is bonded in a bent 150 degrees geometry to one Mg(1) and one Sb(1) atom. In the fourth F site, F(4) is bonded in a distorted bent 120 degrees geometry to one Mg(1) and one Sb(1) atom. In the fifth F site, F(5) is bonded in a bent 150 degrees geometry to one Mg(1) and one Sb(1) atom.