Sr2LaF7 crystallizes in the monoclinic Cm space group. There are four inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 9-coordinate geometry to one F(10), one F(12), one F(4), three equivalent F(14), and three equivalent F(2) atoms. In the second Sr site, Sr(2) is bonded in a 7-coordinate geometry to one F(6), three equivalent F(1), and three equivalent F(4) atoms. In the third Sr site, Sr(3) is bonded in a body-centered cubic geometry to one F(1), one F(8), three equivalent F(3), and three equivalent F(6) atoms. In the fourth Sr site, Sr(4) is bonded in a body-centered cubic geometry to one F(11), one F(3), three equivalent F(5), and three equivalent F(8) atoms. There are two inequivalent La sites. In the first La site, La(1) is bonded in a 11-coordinate geometry to one F(13), one F(5), three equivalent F(11), three equivalent F(7), and three equivalent F(9) atoms. In the second La site, La(2) is bonded in a 10-coordinate geometry to one F(14), three equivalent F(10), three equivalent F(12), and three equivalent F(13) atoms. There are fourteen inequivalent F sites. In the first F site, F(1) is bonded to one Sr(3) and three equivalent Sr(2) atoms to form a mixture of corner and edge-sharing FSr4 tetrahedra. In the second F site, F(2) is bonded in a 3-coordinate geometry to three equivalent Sr(1) atoms. In the third F site, F(3) is bonded to one Sr(4) and three equivalent Sr(3) atoms to form FSr4 tetrahedra that share  a cornercorner with one F(11)SrLa3 tetrahedra, corners with three equivalent F(5)Sr3La tetrahedra, corners with three equivalent F(1)Sr4 tetrahedra, corners with three equivalent F(6)Sr4 tetrahedra, corners with six equivalent F(3)Sr4 tetrahedra, edges with three equivalent F(6)Sr4 tetrahedra, and edges with three equivalent F(8)Sr4 tetrahedra. In the fourth F site, F(4) is bonded to one Sr(1) and three equivalent Sr(2) atoms to form FSr4 tetrahedra that share corners with three equivalent F(14)Sr3La tetrahedra, corners with three equivalent F(1)Sr4 tetrahedra, corners with three equivalent F(6)Sr4 tetrahedra, corners with six equivalent F(4)Sr4 tetrahedra, and edges with three equivalent F(1)Sr4 tetrahedra. In the fifth F site, F(5) is bonded to three equivalent Sr(4) and one La(1) atom to form FSr3La tetrahedra that share  a cornercorner with one F(13)La4 tetrahedra, corners with three equivalent F(3)Sr4 tetrahedra, corners with three equivalent F(8)Sr4 tetrahedra, corners with six equivalent F(5)Sr3La tetrahedra, edges with three equivalent F(8)Sr4 tetrahedra, and edges with three equivalent F(11)SrLa3 tetrahedra. In the sixth F site, F(6) is bonded to one Sr(2) and three equivalent Sr(3) atoms to form a mixture of corner and edge-sharing FSr4 tetrahedra. In the seventh F site, F(7) is bonded in a trigonal planar geometry to three equivalent La(1) atoms. In the eighth F site, F(8) is bonded to one Sr(3) and three equivalent Sr(4) atoms to form FSr4 tetrahedra that share  a cornercorner with one F(1)Sr4 tetrahedra, corners with three equivalent F(5)Sr3La tetrahedra, corners with three equivalent F(6)Sr4 tetrahedra, corners with three equivalent F(11)SrLa3 tetrahedra, corners with six equivalent F(8)Sr4 tetrahedra, edges with three equivalent F(5)Sr3La tetrahedra, and edges with three equivalent F(3)Sr4 tetrahedra. In the ninth F site, F(9) is bonded in a 3-coordinate geometry to three equivalent La(1) atoms. In the tenth F site, F(10) is bonded in a distorted trigonal planar geometry to one Sr(1) and three equivalent La(2) atoms. In the eleventh F site, F(11) is bonded to one Sr(4) and three equivalent La(1) atoms to form distorted FSrLa3 tetrahedra that share  a cornercorner with one F(3)Sr4 tetrahedra, corners with three equivalent F(13)La4 tetrahedra, corners with three equivalent F(8)Sr4 tetrahedra, corners with six equivalent F(11)SrLa3 tetrahedra, and edges with three equivalent F(5)Sr3La tetrahedra. In the twelfth F site, F(12) is bonded in a 4-coordinate geometry to one Sr(1) and three equivalent La(2) atoms. In the thirteenth F site, F(13) is bonded to one La(1) and three equivalent La(2) atoms to form FLa4 tetrahedra that share  a cornercorner with one F(5)Sr3La tetrahedra, corners with three equivalent F(14)Sr3La tetrahedra, corners with three equivalent F(11)SrLa3 tetrahedra, and corners with six equivalent F(13)La4 tetrahedra. In the fourteenth F site, F(14) is bonded to three equivalent Sr(1) and one La(2) atom to form distorted FSr3La tetrahedra that share corners with three equivalent F(13)La4 tetrahedra, corners with three equivalent F(4)Sr4 tetrahedra, and corners with six equivalent F(14)Sr3La tetrahedra.
Sr2LaF7 crystallizes in the monoclinic Cm space group. There are four inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 9-coordinate geometry to one F(10), one F(12), one F(4), three equivalent F(14), and three equivalent F(2) atoms. The Sr(1)-F(10) bond length is 3.02 Å. The Sr(1)-F(12) bond length is 2.90 Å. The Sr(1)-F(4) bond length is 2.64 Å. There are two shorter (2.49 Å) and one longer (2.93 Å) Sr(1)-F(14) bond length. There is one shorter (2.50 Å) and two longer (2.79 Å) Sr(1)-F(2) bond lengths. In the second Sr site, Sr(2) is bonded in a 7-coordinate geometry to one F(6), three equivalent F(1), and three equivalent F(4) atoms. The Sr(2)-F(6) bond length is 2.57 Å. There are two shorter (2.56 Å) and one longer (2.57 Å) Sr(2)-F(1) bond length. There is one shorter (2.51 Å) and two longer (2.55 Å) Sr(2)-F(4) bond lengths. In the third Sr site, Sr(3) is bonded in a body-centered cubic geometry to one F(1), one F(8), three equivalent F(3), and three equivalent F(6) atoms. The Sr(3)-F(1) bond length is 2.50 Å. The Sr(3)-F(8) bond length is 2.60 Å. There are two shorter (2.54 Å) and one longer (2.56 Å) Sr(3)-F(3) bond length. There are two shorter (2.53 Å) and one longer (2.55 Å) Sr(3)-F(6) bond length. In the fourth Sr site, Sr(4) is bonded in a body-centered cubic geometry to one F(11), one F(3), three equivalent F(5), and three equivalent F(8) atoms. The Sr(4)-F(11) bond length is 2.45 Å. The Sr(4)-F(3) bond length is 2.57 Å. There are two shorter (2.57 Å) and one longer (2.63 Å) Sr(4)-F(5) bond length. There are two shorter (2.53 Å) and one longer (2.55 Å) Sr(4)-F(8) bond length. There are two inequivalent La sites. In the first La site, La(1) is bonded in a 11-coordinate geometry to one F(13), one F(5), three equivalent F(11), three equivalent F(7), and three equivalent F(9) atoms. The La(1)-F(13) bond length is 2.49 Å. The La(1)-F(5) bond length is 2.66 Å. There are two shorter (2.64 Å) and one longer (2.75 Å) La(1)-F(11) bond length. All La(1)-F(7) bond lengths are 2.40 Å. There are two shorter (2.69 Å) and one longer (2.76 Å) La(1)-F(9) bond length. In the second La site, La(2) is bonded in a 10-coordinate geometry to one F(14), three equivalent F(10), three equivalent F(12), and three equivalent F(13) atoms. The La(2)-F(14) bond length is 2.32 Å. There is one shorter (2.40 Å) and two longer (2.43 Å) La(2)-F(10) bond lengths. There are two shorter (2.73 Å) and one longer (2.87 Å) La(2)-F(12) bond length. There are two shorter (2.61 Å) and one longer (2.76 Å) La(2)-F(13) bond length. There are fourteen inequivalent F sites. In the first F site, F(1) is bonded to one Sr(3) and three equivalent Sr(2) atoms to form a mixture of corner and edge-sharing FSr4 tetrahedra. In the second F site, F(2) is bonded in a 3-coordinate geometry to three equivalent Sr(1) atoms. In the third F site, F(3) is bonded to one Sr(4) and three equivalent Sr(3) atoms to form FSr4 tetrahedra that share  a cornercorner with one F(11)SrLa3 tetrahedra, corners with three equivalent F(5)Sr3La tetrahedra, corners with three equivalent F(1)Sr4 tetrahedra, corners with three equivalent F(6)Sr4 tetrahedra, corners with six equivalent F(3)Sr4 tetrahedra, edges with three equivalent F(6)Sr4 tetrahedra, and edges with three equivalent F(8)Sr4 tetrahedra. In the fourth F site, F(4) is bonded to one Sr(1) and three equivalent Sr(2) atoms to form FSr4 tetrahedra that share corners with three equivalent F(14)Sr3La tetrahedra, corners with three equivalent F(1)Sr4 tetrahedra, corners with three equivalent F(6)Sr4 tetrahedra, corners with six equivalent F(4)Sr4 tetrahedra, and edges with three equivalent F(1)Sr4 tetrahedra. In the fifth F site, F(5) is bonded to three equivalent Sr(4) and one La(1) atom to form FSr3La tetrahedra that share  a cornercorner with one F(13)La4 tetrahedra, corners with three equivalent F(3)Sr4 tetrahedra, corners with three equivalent F(8)Sr4 tetrahedra, corners with six equivalent F(5)Sr3La tetrahedra, edges with three equivalent F(8)Sr4 tetrahedra, and edges with three equivalent F(11)SrLa3 tetrahedra. In the sixth F site, F(6) is bonded to one Sr(2) and three equivalent Sr(3) atoms to form a mixture of corner and edge-sharing FSr4 tetrahedra. In the seventh F site, F(7) is bonded in a trigonal planar geometry to three equivalent La(1) atoms. In the eighth F site, F(8) is bonded to one Sr(3) and three equivalent Sr(4) atoms to form FSr4 tetrahedra that share  a cornercorner with one F(1)Sr4 tetrahedra, corners with three equivalent F(5)Sr3La tetrahedra, corners with three equivalent F(6)Sr4 tetrahedra, corners with three equivalent F(11)SrLa3 tetrahedra, corners with six equivalent F(8)Sr4 tetrahedra, edges with three equivalent F(5)Sr3La tetrahedra, and edges with three equivalent F(3)Sr4 tetrahedra. In the ninth F site, F(9) is bonded in a 3-coordinate geometry to three equivalent La(1) atoms. In the tenth F site, F(10) is bonded in a distorted trigonal planar geometry to one Sr(1) and three equivalent La(2) atoms. In the eleventh F site, F(11) is bonded to one Sr(4) and three equivalent La(1) atoms to form distorted FSrLa3 tetrahedra that share  a cornercorner with one F(3)Sr4 tetrahedra, corners with three equivalent F(13)La4 tetrahedra, corners with three equivalent F(8)Sr4 tetrahedra, corners with six equivalent F(11)SrLa3 tetrahedra, and edges with three equivalent F(5)Sr3La tetrahedra. In the twelfth F site, F(12) is bonded in a 4-coordinate geometry to one Sr(1) and three equivalent La(2) atoms. In the thirteenth F site, F(13) is bonded to one La(1) and three equivalent La(2) atoms to form FLa4 tetrahedra that share  a cornercorner with one F(5)Sr3La tetrahedra, corners with three equivalent F(14)Sr3La tetrahedra, corners with three equivalent F(11)SrLa3 tetrahedra, and corners with six equivalent F(13)La4 tetrahedra. In the fourteenth F site, F(14) is bonded to three equivalent Sr(1) and one La(2) atom to form distorted FSr3La tetrahedra that share corners with three equivalent F(13)La4 tetrahedra, corners with three equivalent F(4)Sr4 tetrahedra, and corners with six equivalent F(14)Sr3La tetrahedra.