SrMgF4 crystallizes in the monoclinic P2_1/m space group. There are four inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 8-coordinate geometry to one F(1), one F(11), one F(4), one F(6), one F(7), one F(9), and two equivalent F(10) atoms. In the second Sr site, Sr(2) is bonded in a 8-coordinate geometry to two equivalent F(5), two equivalent F(6), two equivalent F(7), and two equivalent F(9) atoms. In the third Sr site, Sr(3) is bonded in a 8-coordinate geometry to one F(10), one F(11), one F(12), one F(2), one F(5), one F(9), and two equivalent F(1) atoms. In the fourth Sr site, Sr(4) is bonded in a 8-coordinate geometry to two equivalent F(11), two equivalent F(2), two equivalent F(5), and two equivalent F(6) atoms. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one F(12), one F(4), two equivalent F(8), and two equivalent F(9) atoms to form corner-sharing MgF6 octahedra. The corner-sharing octahedral tilt angles range from 4-14°. In the second Mg site, Mg(2) is bonded to one F(1), one F(13), one F(2), one F(3), one F(5), and one F(7) atom to form corner-sharing MgF6 octahedra. The corner-sharing octahedral tilt angles range from 0-12°. In the third Mg site, Mg(3) is bonded to one F(10), one F(14), one F(2), one F(6), one F(7), and one F(8) atom to form corner-sharing MgF6 octahedra. The corner-sharing octahedral tilt angles range from 0-12°. In the fourth Mg site, Mg(4) is bonded to one F(12), one F(4), two equivalent F(11), and two equivalent F(3) atoms to form corner-sharing MgF6 octahedra. The corner-sharing octahedral tilt angles range from 4-14°. There are fourteen inequivalent F sites. In the first F site, F(1) is bonded to one Sr(1), two equivalent Sr(3), and one Mg(2) atom to form a mixture of distorted corner and edge-sharing FSr3Mg tetrahedra. In the second F site, F(2) is bonded in a distorted linear geometry to one Sr(3), one Sr(4), one Mg(2), and one Mg(3) atom. In the third F site, F(3) is bonded in a linear geometry to one Mg(2) and one Mg(4) atom. In the fourth F site, F(4) is bonded in a linear geometry to two equivalent Sr(1), one Mg(1), and one Mg(4) atom. In the fifth F site, F(5) is bonded to one Sr(2), one Sr(3), one Sr(4), and one Mg(2) atom to form a mixture of corner and edge-sharing FSr3Mg tetrahedra. In the sixth F site, F(6) is bonded to one Sr(1), one Sr(2), one Sr(4), and one Mg(3) atom to form a mixture of corner and edge-sharing FSr3Mg tetrahedra. In the seventh F site, F(7) is bonded in a distorted linear geometry to one Sr(1), one Sr(2), one Mg(2), and one Mg(3) atom. In the eighth F site, F(8) is bonded in a linear geometry to one Mg(1) and one Mg(3) atom. In the ninth F site, F(9) is bonded to one Sr(1), one Sr(2), one Sr(3), and one Mg(1) atom to form a mixture of corner and edge-sharing FSr3Mg tetrahedra. In the tenth F site, F(10) is bonded to one Sr(3), two equivalent Sr(1), and one Mg(3) atom to form a mixture of corner and edge-sharing FSr3Mg tetrahedra. In the eleventh F site, F(11) is bonded to one Sr(1), one Sr(3), one Sr(4), and one Mg(4) atom to form a mixture of corner and edge-sharing FSr3Mg tetrahedra. In the twelfth F site, F(12) is bonded in a distorted linear geometry to two equivalent Sr(3), one Mg(1), and one Mg(4) atom. In the thirteenth F site, F(13) is bonded in a linear geometry to two equivalent Mg(2) atoms. In the fourteenth F site, F(14) is bonded in a linear geometry to two equivalent Mg(3) atoms.
SrMgF4 crystallizes in the monoclinic P2_1/m space group. There are four inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 8-coordinate geometry to one F(1), one F(11), one F(4), one F(6), one F(7), one F(9), and two equivalent F(10) atoms. The Sr(1)-F(1) bond length is 2.49 Å. The Sr(1)-F(11) bond length is 2.49 Å. The Sr(1)-F(4) bond length is 3.03 Å. The Sr(1)-F(6) bond length is 2.59 Å. The Sr(1)-F(7) bond length is 2.91 Å. The Sr(1)-F(9) bond length is 2.49 Å. There is one shorter (2.49 Å) and one longer (2.56 Å) Sr(1)-F(10) bond length. In the second Sr site, Sr(2) is bonded in a 8-coordinate geometry to two equivalent F(5), two equivalent F(6), two equivalent F(7), and two equivalent F(9) atoms. Both Sr(2)-F(5) bond lengths are 2.50 Å. Both Sr(2)-F(6) bond lengths are 2.50 Å. Both Sr(2)-F(7) bond lengths are 3.00 Å. Both Sr(2)-F(9) bond lengths are 2.60 Å. In the third Sr site, Sr(3) is bonded in a 8-coordinate geometry to one F(10), one F(11), one F(12), one F(2), one F(5), one F(9), and two equivalent F(1) atoms. The Sr(3)-F(10) bond length is 2.49 Å. The Sr(3)-F(11) bond length is 2.50 Å. The Sr(3)-F(12) bond length is 2.94 Å. The Sr(3)-F(2) bond length is 3.02 Å. The Sr(3)-F(5) bond length is 2.56 Å. The Sr(3)-F(9) bond length is 2.50 Å. There is one shorter (2.49 Å) and one longer (2.61 Å) Sr(3)-F(1) bond length. In the fourth Sr site, Sr(4) is bonded in a 8-coordinate geometry to two equivalent F(11), two equivalent F(2), two equivalent F(5), and two equivalent F(6) atoms. Both Sr(4)-F(11) bond lengths are 2.58 Å. Both Sr(4)-F(2) bond lengths are 2.98 Å. Both Sr(4)-F(5) bond lengths are 2.49 Å. Both Sr(4)-F(6) bond lengths are 2.49 Å. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one F(12), one F(4), two equivalent F(8), and two equivalent F(9) atoms to form corner-sharing MgF6 octahedra. The corner-sharing octahedral tilt angles range from 4-14°. The Mg(1)-F(12) bond length is 2.05 Å. The Mg(1)-F(4) bond length is 2.04 Å. Both Mg(1)-F(8) bond lengths are 1.93 Å. Both Mg(1)-F(9) bond lengths are 2.02 Å. In the second Mg site, Mg(2) is bonded to one F(1), one F(13), one F(2), one F(3), one F(5), and one F(7) atom to form corner-sharing MgF6 octahedra. The corner-sharing octahedral tilt angles range from 0-12°. The Mg(2)-F(1) bond length is 2.01 Å. The Mg(2)-F(13) bond length is 1.94 Å. The Mg(2)-F(2) bond length is 2.05 Å. The Mg(2)-F(3) bond length is 1.93 Å. The Mg(2)-F(5) bond length is 2.03 Å. The Mg(2)-F(7) bond length is 2.05 Å. In the third Mg site, Mg(3) is bonded to one F(10), one F(14), one F(2), one F(6), one F(7), and one F(8) atom to form corner-sharing MgF6 octahedra. The corner-sharing octahedral tilt angles range from 0-12°. The Mg(3)-F(10) bond length is 2.02 Å. The Mg(3)-F(14) bond length is 1.93 Å. The Mg(3)-F(2) bond length is 2.04 Å. The Mg(3)-F(6) bond length is 2.02 Å. The Mg(3)-F(7) bond length is 2.05 Å. The Mg(3)-F(8) bond length is 1.93 Å. In the fourth Mg site, Mg(4) is bonded to one F(12), one F(4), two equivalent F(11), and two equivalent F(3) atoms to form corner-sharing MgF6 octahedra. The corner-sharing octahedral tilt angles range from 4-14°. The Mg(4)-F(12) bond length is 2.05 Å. The Mg(4)-F(4) bond length is 2.04 Å. Both Mg(4)-F(11) bond lengths are 2.02 Å. Both Mg(4)-F(3) bond lengths are 1.93 Å. There are fourteen inequivalent F sites. In the first F site, F(1) is bonded to one Sr(1), two equivalent Sr(3), and one Mg(2) atom to form a mixture of distorted corner and edge-sharing FSr3Mg tetrahedra. In the second F site, F(2) is bonded in a distorted linear geometry to one Sr(3), one Sr(4), one Mg(2), and one Mg(3) atom. In the third F site, F(3) is bonded in a linear geometry to one Mg(2) and one Mg(4) atom. In the fourth F site, F(4) is bonded in a linear geometry to two equivalent Sr(1), one Mg(1), and one Mg(4) atom. In the fifth F site, F(5) is bonded to one Sr(2), one Sr(3), one Sr(4), and one Mg(2) atom to form a mixture of corner and edge-sharing FSr3Mg tetrahedra. In the sixth F site, F(6) is bonded to one Sr(1), one Sr(2), one Sr(4), and one Mg(3) atom to form a mixture of corner and edge-sharing FSr3Mg tetrahedra. In the seventh F site, F(7) is bonded in a distorted linear geometry to one Sr(1), one Sr(2), one Mg(2), and one Mg(3) atom. In the eighth F site, F(8) is bonded in a linear geometry to one Mg(1) and one Mg(3) atom. In the ninth F site, F(9) is bonded to one Sr(1), one Sr(2), one Sr(3), and one Mg(1) atom to form a mixture of corner and edge-sharing FSr3Mg tetrahedra. In the tenth F site, F(10) is bonded to one Sr(3), two equivalent Sr(1), and one Mg(3) atom to form a mixture of corner and edge-sharing FSr3Mg tetrahedra. In the eleventh F site, F(11) is bonded to one Sr(1), one Sr(3), one Sr(4), and one Mg(4) atom to form a mixture of corner and edge-sharing FSr3Mg tetrahedra. In the twelfth F site, F(12) is bonded in a distorted linear geometry to two equivalent Sr(3), one Mg(1), and one Mg(4) atom. In the thirteenth F site, F(13) is bonded in a linear geometry to two equivalent Mg(2) atoms. In the fourteenth F site, F(14) is bonded in a linear geometry to two equivalent Mg(3) atoms.