Sm2Zr8O19 is alpha bismuth trifluoride-derived structured and crystallizes in the orthorhombic Pmm2 space group. There are two inequivalent Sm sites. In the first Sm site, Sm(1) is bonded in a 6-coordinate geometry to two equivalent O(19), two equivalent O(6), and two equivalent O(7) atoms. In the second Sm site, Sm(2) is bonded to two equivalent O(10), two equivalent O(7), and two equivalent O(8) atoms to form a mixture of distorted corner and edge-sharing SmO6 octahedra. The corner-sharing octahedral tilt angles are 59°. There are eight inequivalent Zr sites. In the first Zr site, Zr(1) is bonded in a body-centered cubic geometry to two equivalent O(10), two equivalent O(11), two equivalent O(8), and two equivalent O(9) atoms. In the second Zr site, Zr(2) is bonded in a body-centered cubic geometry to two equivalent O(11), two equivalent O(12), two equivalent O(13), and two equivalent O(9) atoms. In the third Zr site, Zr(3) is bonded in a body-centered cubic geometry to two equivalent O(1), two equivalent O(12), two equivalent O(13), and two equivalent O(14) atoms. In the fourth Zr site, Zr(4) is bonded in a body-centered cubic geometry to two equivalent O(1), two equivalent O(14), two equivalent O(15), and two equivalent O(2) atoms. In the fifth Zr site, Zr(5) is bonded in a body-centered cubic geometry to two equivalent O(15), two equivalent O(16), two equivalent O(2), and two equivalent O(3) atoms. In the sixth Zr site, Zr(6) is bonded in a body-centered cubic geometry to two equivalent O(16), two equivalent O(17), two equivalent O(3), and two equivalent O(4) atoms. In the seventh Zr site, Zr(7) is bonded in a body-centered cubic geometry to two equivalent O(17), two equivalent O(18), two equivalent O(4), and two equivalent O(5) atoms. In the eighth Zr site, Zr(8) is bonded in a body-centered cubic geometry to two equivalent O(18), two equivalent O(19), two equivalent O(5), and two equivalent O(6) atoms. There are nineteen inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Zr(3) and two equivalent Zr(4) atoms to form a mixture of corner and edge-sharing OZr4 tetrahedra. In the second O site, O(2) is bonded to two equivalent Zr(4) and two equivalent Zr(5) atoms to form a mixture of corner and edge-sharing OZr4 tetrahedra. In the third O site, O(3) is bonded to two equivalent Zr(5) and two equivalent Zr(6) atoms to form a mixture of corner and edge-sharing OZr4 tetrahedra. In the fourth O site, O(4) is bonded to two equivalent Zr(6) and two equivalent Zr(7) atoms to form a mixture of corner and edge-sharing OZr4 tetrahedra. In the fifth O site, O(5) is bonded to two equivalent Zr(7) and two equivalent Zr(8) atoms to form OZr4 tetrahedra that share corners with two equivalent O(19)Sm2Zr2 tetrahedra, corners with two equivalent O(17)Zr4 tetrahedra, corners with four equivalent O(6)Sm2Zr2 tetrahedra, corners with four equivalent O(4)Zr4 tetrahedra, corners with four equivalent O(5)Zr4 tetrahedra,  an edgeedge with one O(19)Sm2Zr2 tetrahedra,  an edgeedge with one O(17)Zr4 tetrahedra, and edges with four equivalent O(18)Zr4 tetrahedra. In the sixth O site, O(6) is bonded to two equivalent Sm(1) and two equivalent Zr(8) atoms to form OSm2Zr2 tetrahedra that share corners with two equivalent O(7)Sm4 tetrahedra, corners with two equivalent O(18)Zr4 tetrahedra, corners with four equivalent O(6)Sm2Zr2 tetrahedra, corners with four equivalent O(5)Zr4 tetrahedra,  an edgeedge with one O(7)Sm4 tetrahedra,  an edgeedge with one O(18)Zr4 tetrahedra, and edges with four equivalent O(19)Sm2Zr2 tetrahedra. In the seventh O site, O(7) is bonded to two equivalent Sm(1) and two equivalent Sm(2) atoms to form OSm4 tetrahedra that share corners with two equivalent O(6)Sm2Zr2 tetrahedra, corners with two equivalent O(8)Sm2Zr2 tetrahedra, corners with four equivalent O(10)Sm2Zr2 tetrahedra, corners with four equivalent O(19)Sm2Zr2 tetrahedra, corners with four equivalent O(7)Sm4 tetrahedra,  an edgeedge with one O(6)Sm2Zr2 tetrahedra, and  an edgeedge with one O(8)Sm2Zr2 tetrahedra. In the eighth O site, O(8) is bonded to two equivalent Sm(2) and two equivalent Zr(1) atoms to form OSm2Zr2 tetrahedra that share corners with two equivalent O(7)Sm4 tetrahedra, corners with two equivalent O(11)Zr4 tetrahedra, corners with four equivalent O(8)Sm2Zr2 tetrahedra, corners with four equivalent O(9)Zr4 tetrahedra,  an edgeedge with one O(7)Sm4 tetrahedra,  an edgeedge with one O(11)Zr4 tetrahedra, and edges with four equivalent O(10)Sm2Zr2 tetrahedra. In the ninth O site, O(9) is bonded to two equivalent Zr(1) and two equivalent Zr(2) atoms to form OZr4 tetrahedra that share corners with two equivalent O(10)Sm2Zr2 tetrahedra, corners with two equivalent O(13)Zr4 tetrahedra, corners with four equivalent O(8)Sm2Zr2 tetrahedra, corners with four equivalent O(12)Zr4 tetrahedra, corners with four equivalent O(9)Zr4 tetrahedra,  an edgeedge with one O(10)Sm2Zr2 tetrahedra,  an edgeedge with one O(13)Zr4 tetrahedra, and edges with four equivalent O(11)Zr4 tetrahedra. In the tenth O site, O(10) is bonded to two equivalent Sm(2) and two equivalent Zr(1) atoms to form OSm2Zr2 tetrahedra that share corners with two equivalent O(9)Zr4 tetrahedra, corners with four equivalent O(10)Sm2Zr2 tetrahedra, corners with four equivalent O(7)Sm4 tetrahedra, corners with four equivalent O(11)Zr4 tetrahedra,  an edgeedge with one O(9)Zr4 tetrahedra, and edges with four equivalent O(8)Sm2Zr2 tetrahedra. In the eleventh O site, O(11) is bonded to two equivalent Zr(1) and two equivalent Zr(2) atoms to form OZr4 tetrahedra that share corners with two equivalent O(8)Sm2Zr2 tetrahedra, corners with two equivalent O(12)Zr4 tetrahedra, corners with four equivalent O(10)Sm2Zr2 tetrahedra, corners with four equivalent O(11)Zr4 tetrahedra, corners with four equivalent O(13)Zr4 tetrahedra,  an edgeedge with one O(8)Sm2Zr2 tetrahedra,  an edgeedge with one O(12)Zr4 tetrahedra, and edges with four equivalent O(9)Zr4 tetrahedra. In the twelfth O site, O(12) is bonded to two equivalent Zr(2) and two equivalent Zr(3) atoms to form a mixture of corner and edge-sharing OZr4 tetrahedra. In the thirteenth O site, O(13) is bonded to two equivalent Zr(2) and two equivalent Zr(3) atoms to form a mixture of corner and edge-sharing OZr4 tetrahedra. In the fourteenth O site, O(14) is bonded to two equivalent Zr(3) and two equivalent Zr(4) atoms to form a mixture of corner and edge-sharing OZr4 tetrahedra. In the fifteenth O site, O(15) is bonded to two equivalent Zr(4) and two equivalent Zr(5) atoms to form a mixture of corner and edge-sharing OZr4 tetrahedra. In the sixteenth O site, O(16) is bonded to two equivalent Zr(5) and two equivalent Zr(6) atoms to form a mixture of corner and edge-sharing OZr4 tetrahedra. In the seventeenth O site, O(17) is bonded to two equivalent Zr(6) and two equivalent Zr(7) atoms to form a mixture of corner and edge-sharing OZr4 tetrahedra. In the eighteenth O site, O(18) is bonded to two equivalent Zr(7) and two equivalent Zr(8) atoms to form OZr4 tetrahedra that share corners with two equivalent O(6)Sm2Zr2 tetrahedra, corners with two equivalent O(4)Zr4 tetrahedra, corners with four equivalent O(19)Sm2Zr2 tetrahedra, corners with four equivalent O(17)Zr4 tetrahedra, corners with four equivalent O(18)Zr4 tetrahedra,  an edgeedge with one O(6)Sm2Zr2 tetrahedra,  an edgeedge with one O(4)Zr4 tetrahedra, and edges with four equivalent O(5)Zr4 tetrahedra. In the nineteenth O site, O(19) is bonded to two equivalent Sm(1) and two equivalent Zr(8) atoms to form OSm2Zr2 tetrahedra that share corners with two equivalent O(5)Zr4 tetrahedra, corners with four equivalent O(19)Sm2Zr2 tetrahedra, corners with four equivalent O(7)Sm4 tetrahedra, corners with four equivalent O(18)Zr4 tetrahedra,  an edgeedge with one O(5)Zr4 tetrahedra, and edges with four equivalent O(6)Sm2Zr2 tetrahedra.
Sm2Zr8O19 is alpha bismuth trifluoride-derived structured and crystallizes in the orthorhombic Pmm2 space group. There are two inequivalent Sm sites. In the first Sm site, Sm(1) is bonded in a 6-coordinate geometry to two equivalent O(19), two equivalent O(6), and two equivalent O(7) atoms. Both Sm(1)-O(19) bond lengths are 2.20 Å. Both Sm(1)-O(6) bond lengths are 2.32 Å. Both Sm(1)-O(7) bond lengths are 2.29 Å. In the second Sm site, Sm(2) is bonded to two equivalent O(10), two equivalent O(7), and two equivalent O(8) atoms to form a mixture of distorted corner and edge-sharing SmO6 octahedra. The corner-sharing octahedral tilt angles are 59°. Both Sm(2)-O(10) bond lengths are 2.13 Å. Both Sm(2)-O(7) bond lengths are 2.50 Å. Both Sm(2)-O(8) bond lengths are 2.31 Å. There are eight inequivalent Zr sites. In the first Zr site, Zr(1) is bonded in a body-centered cubic geometry to two equivalent O(10), two equivalent O(11), two equivalent O(8), and two equivalent O(9) atoms. Both Zr(1)-O(10) bond lengths are 2.37 Å. Both Zr(1)-O(11) bond lengths are 2.30 Å. Both Zr(1)-O(8) bond lengths are 2.18 Å. Both Zr(1)-O(9) bond lengths are 2.10 Å. In the second Zr site, Zr(2) is bonded in a body-centered cubic geometry to two equivalent O(11), two equivalent O(12), two equivalent O(13), and two equivalent O(9) atoms. Both Zr(2)-O(11) bond lengths are 2.16 Å. Both Zr(2)-O(12) bond lengths are 2.25 Å. Both Zr(2)-O(13) bond lengths are 2.15 Å. Both Zr(2)-O(9) bond lengths are 2.37 Å. In the third Zr site, Zr(3) is bonded in a body-centered cubic geometry to two equivalent O(1), two equivalent O(12), two equivalent O(13), and two equivalent O(14) atoms. Both Zr(3)-O(1) bond lengths are 2.14 Å. Both Zr(3)-O(12) bond lengths are 2.21 Å. Both Zr(3)-O(13) bond lengths are 2.32 Å. Both Zr(3)-O(14) bond lengths are 2.25 Å. In the fourth Zr site, Zr(4) is bonded in a body-centered cubic geometry to two equivalent O(1), two equivalent O(14), two equivalent O(15), and two equivalent O(2) atoms. Both Zr(4)-O(1) bond lengths are 2.31 Å. Both Zr(4)-O(14) bond lengths are 2.20 Å. Both Zr(4)-O(15) bond lengths are 2.19 Å. Both Zr(4)-O(2) bond lengths are 2.20 Å. In the fifth Zr site, Zr(5) is bonded in a body-centered cubic geometry to two equivalent O(15), two equivalent O(16), two equivalent O(2), and two equivalent O(3) atoms. Both Zr(5)-O(15) bond lengths are 2.27 Å. Both Zr(5)-O(16) bond lengths are 2.21 Å. Both Zr(5)-O(2) bond lengths are 2.24 Å. Both Zr(5)-O(3) bond lengths are 2.18 Å. In the sixth Zr site, Zr(6) is bonded in a body-centered cubic geometry to two equivalent O(16), two equivalent O(17), two equivalent O(3), and two equivalent O(4) atoms. Both Zr(6)-O(16) bond lengths are 2.24 Å. Both Zr(6)-O(17) bond lengths are 2.23 Å. Both Zr(6)-O(3) bond lengths are 2.27 Å. Both Zr(6)-O(4) bond lengths are 2.16 Å. In the seventh Zr site, Zr(7) is bonded in a body-centered cubic geometry to two equivalent O(17), two equivalent O(18), two equivalent O(4), and two equivalent O(5) atoms. Both Zr(7)-O(17) bond lengths are 2.23 Å. Both Zr(7)-O(18) bond lengths are 2.18 Å. Both Zr(7)-O(4) bond lengths are 2.29 Å. Both Zr(7)-O(5) bond lengths are 2.22 Å. In the eighth Zr site, Zr(8) is bonded in a body-centered cubic geometry to two equivalent O(18), two equivalent O(19), two equivalent O(5), and two equivalent O(6) atoms. Both Zr(8)-O(18) bond lengths are 2.28 Å. Both Zr(8)-O(19) bond lengths are 2.25 Å. Both Zr(8)-O(5) bond lengths are 2.23 Å. Both Zr(8)-O(6) bond lengths are 2.14 Å. There are nineteen inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Zr(3) and two equivalent Zr(4) atoms to form a mixture of corner and edge-sharing OZr4 tetrahedra. In the second O site, O(2) is bonded to two equivalent Zr(4) and two equivalent Zr(5) atoms to form a mixture of corner and edge-sharing OZr4 tetrahedra. In the third O site, O(3) is bonded to two equivalent Zr(5) and two equivalent Zr(6) atoms to form a mixture of corner and edge-sharing OZr4 tetrahedra. In the fourth O site, O(4) is bonded to two equivalent Zr(6) and two equivalent Zr(7) atoms to form a mixture of corner and edge-sharing OZr4 tetrahedra. In the fifth O site, O(5) is bonded to two equivalent Zr(7) and two equivalent Zr(8) atoms to form OZr4 tetrahedra that share corners with two equivalent O(19)Sm2Zr2 tetrahedra, corners with two equivalent O(17)Zr4 tetrahedra, corners with four equivalent O(6)Sm2Zr2 tetrahedra, corners with four equivalent O(4)Zr4 tetrahedra, corners with four equivalent O(5)Zr4 tetrahedra,  an edgeedge with one O(19)Sm2Zr2 tetrahedra,  an edgeedge with one O(17)Zr4 tetrahedra, and edges with four equivalent O(18)Zr4 tetrahedra. In the sixth O site, O(6) is bonded to two equivalent Sm(1) and two equivalent Zr(8) atoms to form OSm2Zr2 tetrahedra that share corners with two equivalent O(7)Sm4 tetrahedra, corners with two equivalent O(18)Zr4 tetrahedra, corners with four equivalent O(6)Sm2Zr2 tetrahedra, corners with four equivalent O(5)Zr4 tetrahedra,  an edgeedge with one O(7)Sm4 tetrahedra,  an edgeedge with one O(18)Zr4 tetrahedra, and edges with four equivalent O(19)Sm2Zr2 tetrahedra. In the seventh O site, O(7) is bonded to two equivalent Sm(1) and two equivalent Sm(2) atoms to form OSm4 tetrahedra that share corners with two equivalent O(6)Sm2Zr2 tetrahedra, corners with two equivalent O(8)Sm2Zr2 tetrahedra, corners with four equivalent O(10)Sm2Zr2 tetrahedra, corners with four equivalent O(19)Sm2Zr2 tetrahedra, corners with four equivalent O(7)Sm4 tetrahedra,  an edgeedge with one O(6)Sm2Zr2 tetrahedra, and  an edgeedge with one O(8)Sm2Zr2 tetrahedra. In the eighth O site, O(8) is bonded to two equivalent Sm(2) and two equivalent Zr(1) atoms to form OSm2Zr2 tetrahedra that share corners with two equivalent O(7)Sm4 tetrahedra, corners with two equivalent O(11)Zr4 tetrahedra, corners with four equivalent O(8)Sm2Zr2 tetrahedra, corners with four equivalent O(9)Zr4 tetrahedra,  an edgeedge with one O(7)Sm4 tetrahedra,  an edgeedge with one O(11)Zr4 tetrahedra, and edges with four equivalent O(10)Sm2Zr2 tetrahedra. In the ninth O site, O(9) is bonded to two equivalent Zr(1) and two equivalent Zr(2) atoms to form OZr4 tetrahedra that share corners with two equivalent O(10)Sm2Zr2 tetrahedra, corners with two equivalent O(13)Zr4 tetrahedra, corners with four equivalent O(8)Sm2Zr2 tetrahedra, corners with four equivalent O(12)Zr4 tetrahedra, corners with four equivalent O(9)Zr4 tetrahedra,  an edgeedge with one O(10)Sm2Zr2 tetrahedra,  an edgeedge with one O(13)Zr4 tetrahedra, and edges with four equivalent O(11)Zr4 tetrahedra. In the tenth O site, O(10) is bonded to two equivalent Sm(2) and two equivalent Zr(1) atoms to form OSm2Zr2 tetrahedra that share corners with two equivalent O(9)Zr4 tetrahedra, corners with four equivalent O(10)Sm2Zr2 tetrahedra, corners with four equivalent O(7)Sm4 tetrahedra, corners with four equivalent O(11)Zr4 tetrahedra,  an edgeedge with one O(9)Zr4 tetrahedra, and edges with four equivalent O(8)Sm2Zr2 tetrahedra. In the eleventh O site, O(11) is bonded to two equivalent Zr(1) and two equivalent Zr(2) atoms to form OZr4 tetrahedra that share corners with two equivalent O(8)Sm2Zr2 tetrahedra, corners with two equivalent O(12)Zr4 tetrahedra, corners with four equivalent O(10)Sm2Zr2 tetrahedra, corners with four equivalent O(11)Zr4 tetrahedra, corners with four equivalent O(13)Zr4 tetrahedra,  an edgeedge with one O(8)Sm2Zr2 tetrahedra,  an edgeedge with one O(12)Zr4 tetrahedra, and edges with four equivalent O(9)Zr4 tetrahedra. In the twelfth O site, O(12) is bonded to two equivalent Zr(2) and two equivalent Zr(3) atoms to form a mixture of corner and edge-sharing OZr4 tetrahedra. In the thirteenth O site, O(13) is bonded to two equivalent Zr(2) and two equivalent Zr(3) atoms to form a mixture of corner and edge-sharing OZr4 tetrahedra. In the fourteenth O site, O(14) is bonded to two equivalent Zr(3) and two equivalent Zr(4) atoms to form a mixture of corner and edge-sharing OZr4 tetrahedra. In the fifteenth O site, O(15) is bonded to two equivalent Zr(4) and two equivalent Zr(5) atoms to form a mixture of corner and edge-sharing OZr4 tetrahedra. In the sixteenth O site, O(16) is bonded to two equivalent Zr(5) and two equivalent Zr(6) atoms to form a mixture of corner and edge-sharing OZr4 tetrahedra. In the seventeenth O site, O(17) is bonded to two equivalent Zr(6) and two equivalent Zr(7) atoms to form a mixture of corner and edge-sharing OZr4 tetrahedra. In the eighteenth O site, O(18) is bonded to two equivalent Zr(7) and two equivalent Zr(8) atoms to form OZr4 tetrahedra that share corners with two equivalent O(6)Sm2Zr2 tetrahedra, corners with two equivalent O(4)Zr4 tetrahedra, corners with four equivalent O(19)Sm2Zr2 tetrahedra, corners with four equivalent O(17)Zr4 tetrahedra, corners with four equivalent O(18)Zr4 tetrahedra,  an edgeedge with one O(6)Sm2Zr2 tetrahedra,  an edgeedge with one O(4)Zr4 tetrahedra, and edges with four equivalent O(5)Zr4 tetrahedra. In the nineteenth O site, O(19) is bonded to two equivalent Sm(1) and two equivalent Zr(8) atoms to form OSm2Zr2 tetrahedra that share corners with two equivalent O(5)Zr4 tetrahedra, corners with four equivalent O(19)Sm2Zr2 tetrahedra, corners with four equivalent O(7)Sm4 tetrahedra, corners with four equivalent O(18)Zr4 tetrahedra,  an edgeedge with one O(5)Zr4 tetrahedra, and edges with four equivalent O(6)Sm2Zr2 tetrahedra.