Na2MgFeF7 crystallizes in the orthorhombic Imma space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded to two equivalent F(1), two equivalent F(3), and four equivalent F(2) atoms to form distorted NaF8 hexagonal bipyramids that share corners with two equivalent Na(1)F8 hexagonal bipyramids, corners with two equivalent Fe(1)F6 octahedra, edges with two equivalent Fe(1)F6 octahedra, and edges with four equivalent Mg(1)F6 octahedra. The corner-sharing octahedral tilt angles are 55°. In the second Na site, Na(2) is bonded in a distorted body-centered cubic geometry to four equivalent F(1) and four equivalent F(2) atoms. Mg(1) is bonded to two equivalent F(3) and four equivalent F(2) atoms to form MgF6 octahedra that share corners with two equivalent Mg(1)F6 octahedra, corners with four equivalent Fe(1)F6 octahedra, and edges with four equivalent Na(1)F8 hexagonal bipyramids. The corner-sharing octahedral tilt angles range from 41-44°. Fe(1) is bonded to two equivalent F(1) and four equivalent F(2) atoms to form FeF6 octahedra that share corners with two equivalent Na(1)F8 hexagonal bipyramids, corners with four equivalent Mg(1)F6 octahedra, and edges with two equivalent Na(1)F8 hexagonal bipyramids. The corner-sharing octahedral tilt angles are 41°. There are three inequivalent F sites. In the first F site, F(1) is bonded to one Na(1), two equivalent Na(2), and one Fe(1) atom to form a mixture of distorted corner and edge-sharing FNa3Fe tetrahedra. In the second F site, F(2) is bonded in a 4-coordinate geometry to one Na(1), one Na(2), one Mg(1), and one Fe(1) atom. In the third F site, F(3) is bonded in a distorted bent 150 degrees geometry to two equivalent Na(1) and two equivalent Mg(1) atoms.
Na2MgFeF7 crystallizes in the orthorhombic Imma space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded to two equivalent F(1), two equivalent F(3), and four equivalent F(2) atoms to form distorted NaF8 hexagonal bipyramids that share corners with two equivalent Na(1)F8 hexagonal bipyramids, corners with two equivalent Fe(1)F6 octahedra, edges with two equivalent Fe(1)F6 octahedra, and edges with four equivalent Mg(1)F6 octahedra. The corner-sharing octahedral tilt angles are 55°. Both Na(1)-F(1) bond lengths are 2.25 Å. Both Na(1)-F(3) bond lengths are 2.85 Å. All Na(1)-F(2) bond lengths are 2.56 Å. In the second Na site, Na(2) is bonded in a distorted body-centered cubic geometry to four equivalent F(1) and four equivalent F(2) atoms. All Na(2)-F(1) bond lengths are 2.46 Å. All Na(2)-F(2) bond lengths are 2.80 Å. Mg(1) is bonded to two equivalent F(3) and four equivalent F(2) atoms to form MgF6 octahedra that share corners with two equivalent Mg(1)F6 octahedra, corners with four equivalent Fe(1)F6 octahedra, and edges with four equivalent Na(1)F8 hexagonal bipyramids. The corner-sharing octahedral tilt angles range from 41-44°. Both Mg(1)-F(3) bond lengths are 1.96 Å. All Mg(1)-F(2) bond lengths are 2.00 Å. Fe(1) is bonded to two equivalent F(1) and four equivalent F(2) atoms to form FeF6 octahedra that share corners with two equivalent Na(1)F8 hexagonal bipyramids, corners with four equivalent Mg(1)F6 octahedra, and edges with two equivalent Na(1)F8 hexagonal bipyramids. The corner-sharing octahedral tilt angles are 41°. Both Fe(1)-F(1) bond lengths are 1.98 Å. All Fe(1)-F(2) bond lengths are 1.95 Å. There are three inequivalent F sites. In the first F site, F(1) is bonded to one Na(1), two equivalent Na(2), and one Fe(1) atom to form a mixture of distorted corner and edge-sharing FNa3Fe tetrahedra. In the second F site, F(2) is bonded in a 4-coordinate geometry to one Na(1), one Na(2), one Mg(1), and one Fe(1) atom. In the third F site, F(3) is bonded in a distorted bent 150 degrees geometry to two equivalent Na(1) and two equivalent Mg(1) atoms.