NaSrMg2F7 crystallizes in the orthorhombic Imma space group. Na(1) is bonded to two equivalent F(1), two equivalent F(3), and four equivalent F(4) atoms to form distorted NaF8 hexagonal bipyramids that share edges with two equivalent Na(1)F8 hexagonal bipyramids, edges with four equivalent Sr(1)F8 hexagonal bipyramids, edges with two equivalent Mg(1)F6 octahedra, and edges with four equivalent Mg(2)F6 octahedra. Sr(1) is bonded to two equivalent F(1), two equivalent F(2), and four equivalent F(4) atoms to form SrF8 hexagonal bipyramids that share edges with two equivalent Sr(1)F8 hexagonal bipyramids, edges with four equivalent Na(1)F8 hexagonal bipyramids, edges with two equivalent Mg(2)F6 octahedra, and edges with four equivalent Mg(1)F6 octahedra. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent F(2) and four equivalent F(4) atoms to form MgF6 octahedra that share corners with two equivalent Mg(1)F6 octahedra, corners with four equivalent Mg(2)F6 octahedra, edges with two equivalent Na(1)F8 hexagonal bipyramids, and edges with four equivalent Sr(1)F8 hexagonal bipyramids. The corner-sharing octahedral tilt angles range from 45-48°. In the second Mg site, Mg(2) is bonded to two equivalent F(3) and four equivalent F(4) atoms to form MgF6 octahedra that share corners with two equivalent Mg(2)F6 octahedra, corners with four equivalent Mg(1)F6 octahedra, edges with two equivalent Sr(1)F8 hexagonal bipyramids, and edges with four equivalent Na(1)F8 hexagonal bipyramids. The corner-sharing octahedral tilt angles range from 41-45°. There are four inequivalent F sites. In the first F site, F(1) is bonded to two equivalent Na(1) and two equivalent Sr(1) atoms to form FNa2Sr2 tetrahedra that share corners with two equivalent F(2)Sr2Mg2 tetrahedra, corners with four equivalent F(1)Na2Sr2 tetrahedra, and  an edgeedge with one F(2)Sr2Mg2 tetrahedra. In the second F site, F(2) is bonded to two equivalent Sr(1) and two equivalent Mg(1) atoms to form distorted FSr2Mg2 tetrahedra that share corners with two equivalent F(1)Na2Sr2 tetrahedra, corners with four equivalent F(2)Sr2Mg2 tetrahedra, and  an edgeedge with one F(1)Na2Sr2 tetrahedra. In the third F site, F(3) is bonded in a 4-coordinate geometry to two equivalent Na(1) and two equivalent Mg(2) atoms. In the fourth F site, F(4) is bonded in a 4-coordinate geometry to one Na(1), one Sr(1), one Mg(1), and one Mg(2) atom.
NaSrMg2F7 crystallizes in the orthorhombic Imma space group. Na(1) is bonded to two equivalent F(1), two equivalent F(3), and four equivalent F(4) atoms to form distorted NaF8 hexagonal bipyramids that share edges with two equivalent Na(1)F8 hexagonal bipyramids, edges with four equivalent Sr(1)F8 hexagonal bipyramids, edges with two equivalent Mg(1)F6 octahedra, and edges with four equivalent Mg(2)F6 octahedra. Both Na(1)-F(1) bond lengths are 2.22 Å. Both Na(1)-F(3) bond lengths are 2.65 Å. All Na(1)-F(4) bond lengths are 2.71 Å. Sr(1) is bonded to two equivalent F(1), two equivalent F(2), and four equivalent F(4) atoms to form SrF8 hexagonal bipyramids that share edges with two equivalent Sr(1)F8 hexagonal bipyramids, edges with four equivalent Na(1)F8 hexagonal bipyramids, edges with two equivalent Mg(2)F6 octahedra, and edges with four equivalent Mg(1)F6 octahedra. Both Sr(1)-F(1) bond lengths are 2.36 Å. Both Sr(1)-F(2) bond lengths are 2.62 Å. All Sr(1)-F(4) bond lengths are 2.58 Å. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent F(2) and four equivalent F(4) atoms to form MgF6 octahedra that share corners with two equivalent Mg(1)F6 octahedra, corners with four equivalent Mg(2)F6 octahedra, edges with two equivalent Na(1)F8 hexagonal bipyramids, and edges with four equivalent Sr(1)F8 hexagonal bipyramids. The corner-sharing octahedral tilt angles range from 45-48°. Both Mg(1)-F(2) bond lengths are 2.02 Å. All Mg(1)-F(4) bond lengths are 2.02 Å. In the second Mg site, Mg(2) is bonded to two equivalent F(3) and four equivalent F(4) atoms to form MgF6 octahedra that share corners with two equivalent Mg(2)F6 octahedra, corners with four equivalent Mg(1)F6 octahedra, edges with two equivalent Sr(1)F8 hexagonal bipyramids, and edges with four equivalent Na(1)F8 hexagonal bipyramids. The corner-sharing octahedral tilt angles range from 41-45°. Both Mg(2)-F(3) bond lengths are 2.04 Å. All Mg(2)-F(4) bond lengths are 2.02 Å. There are four inequivalent F sites. In the first F site, F(1) is bonded to two equivalent Na(1) and two equivalent Sr(1) atoms to form FNa2Sr2 tetrahedra that share corners with two equivalent F(2)Sr2Mg2 tetrahedra, corners with four equivalent F(1)Na2Sr2 tetrahedra, and  an edgeedge with one F(2)Sr2Mg2 tetrahedra. In the second F site, F(2) is bonded to two equivalent Sr(1) and two equivalent Mg(1) atoms to form distorted FSr2Mg2 tetrahedra that share corners with two equivalent F(1)Na2Sr2 tetrahedra, corners with four equivalent F(2)Sr2Mg2 tetrahedra, and  an edgeedge with one F(1)Na2Sr2 tetrahedra. In the third F site, F(3) is bonded in a 4-coordinate geometry to two equivalent Na(1) and two equivalent Mg(2) atoms. In the fourth F site, F(4) is bonded in a 4-coordinate geometry to one Na(1), one Sr(1), one Mg(1), and one Mg(2) atom.