BaMgFeF7 crystallizes in the monoclinic P2_1/c space group. Ba(1) is bonded in a 12-coordinate geometry to one F(1), one F(2), two equivalent F(3), two equivalent F(4), two equivalent F(5), two equivalent F(6), and two equivalent F(7) atoms. Mg(1) is bonded to one F(1), one F(2), one F(3), one F(5), one F(6), and one F(7) atom to form MgF6 octahedra that share corners with three equivalent Fe(1)F6 octahedra and  an edgeedge with one Fe(1)F6 octahedra. The corner-sharing octahedral tilt angles range from 48-53°. Fe(1) is bonded to one F(1), one F(2), one F(3), one F(4), one F(5), and one F(6) atom to form FeF6 octahedra that share corners with three equivalent Mg(1)F6 octahedra and  an edgeedge with one Mg(1)F6 octahedra. The corner-sharing octahedral tilt angles range from 48-53°. There are seven inequivalent F sites. In the first F site, F(1) is bonded in a distorted bent 120 degrees geometry to one Ba(1), one Mg(1), and one Fe(1) atom. In the second F site, F(2) is bonded in a distorted bent 120 degrees geometry to one Ba(1), one Mg(1), and one Fe(1) atom. In the third F site, F(3) is bonded in a distorted water-like geometry to two equivalent Ba(1), one Mg(1), and one Fe(1) atom. In the fourth F site, F(4) is bonded in a distorted single-bond geometry to two equivalent Ba(1) and one Fe(1) atom. In the fifth F site, F(5) is bonded in a distorted bent 120 degrees geometry to two equivalent Ba(1), one Mg(1), and one Fe(1) atom. In the sixth F site, F(6) is bonded in a distorted water-like geometry to two equivalent Ba(1), one Mg(1), and one Fe(1) atom. In the seventh F site, F(7) is bonded in a distorted trigonal planar geometry to two equivalent Ba(1) and one Mg(1) atom.
BaMgFeF7 crystallizes in the monoclinic P2_1/c space group. Ba(1) is bonded in a 12-coordinate geometry to one F(1), one F(2), two equivalent F(3), two equivalent F(4), two equivalent F(5), two equivalent F(6), and two equivalent F(7) atoms. The Ba(1)-F(1) bond length is 3.08 Å. The Ba(1)-F(2) bond length is 3.08 Å. There is one shorter (2.94 Å) and one longer (2.99 Å) Ba(1)-F(3) bond length. There is one shorter (2.72 Å) and one longer (2.77 Å) Ba(1)-F(4) bond length. There is one shorter (3.01 Å) and one longer (3.23 Å) Ba(1)-F(5) bond length. There is one shorter (3.02 Å) and one longer (3.03 Å) Ba(1)-F(6) bond length. There is one shorter (2.63 Å) and one longer (2.65 Å) Ba(1)-F(7) bond length. Mg(1) is bonded to one F(1), one F(2), one F(3), one F(5), one F(6), and one F(7) atom to form MgF6 octahedra that share corners with three equivalent Fe(1)F6 octahedra and  an edgeedge with one Fe(1)F6 octahedra. The corner-sharing octahedral tilt angles range from 48-53°. The Mg(1)-F(1) bond length is 1.99 Å. The Mg(1)-F(2) bond length is 2.03 Å. The Mg(1)-F(3) bond length is 2.11 Å. The Mg(1)-F(5) bond length is 2.04 Å. The Mg(1)-F(6) bond length is 2.05 Å. The Mg(1)-F(7) bond length is 1.92 Å. Fe(1) is bonded to one F(1), one F(2), one F(3), one F(4), one F(5), and one F(6) atom to form FeF6 octahedra that share corners with three equivalent Mg(1)F6 octahedra and  an edgeedge with one Mg(1)F6 octahedra. The corner-sharing octahedral tilt angles range from 48-53°. The Fe(1)-F(1) bond length is 1.96 Å. The Fe(1)-F(2) bond length is 1.94 Å. The Fe(1)-F(3) bond length is 1.99 Å. The Fe(1)-F(4) bond length is 1.91 Å. The Fe(1)-F(5) bond length is 1.99 Å. The Fe(1)-F(6) bond length is 2.02 Å. There are seven inequivalent F sites. In the first F site, F(1) is bonded in a distorted bent 120 degrees geometry to one Ba(1), one Mg(1), and one Fe(1) atom. In the second F site, F(2) is bonded in a distorted bent 120 degrees geometry to one Ba(1), one Mg(1), and one Fe(1) atom. In the third F site, F(3) is bonded in a distorted water-like geometry to two equivalent Ba(1), one Mg(1), and one Fe(1) atom. In the fourth F site, F(4) is bonded in a distorted single-bond geometry to two equivalent Ba(1) and one Fe(1) atom. In the fifth F site, F(5) is bonded in a distorted bent 120 degrees geometry to two equivalent Ba(1), one Mg(1), and one Fe(1) atom. In the sixth F site, F(6) is bonded in a distorted water-like geometry to two equivalent Ba(1), one Mg(1), and one Fe(1) atom. In the seventh F site, F(7) is bonded in a distorted trigonal planar geometry to two equivalent Ba(1) and one Mg(1) atom.