Sr4Y2(Fe2O5)3 crystallizes in the orthorhombic Fmmm space group. Sr(1) is bonded in a 10-coordinate geometry to one O(3), one O(5), two equivalent O(1), two equivalent O(6), and four equivalent O(4) atoms. Y(1) is bonded in a body-centered cubic geometry to two equivalent O(2), two equivalent O(3), and four equivalent O(1) atoms. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(5), two equivalent O(4), and two equivalent O(6) atoms to form corner-sharing FeO5 square pyramids. In the second Fe site, Fe(2) is bonded to one O(2), one O(3), one O(4), and two equivalent O(1) atoms to form distorted corner-sharing FeO5 trigonal bipyramids. There are six inequivalent O sites. In the first O site, O(4) is bonded in a 6-coordinate geometry to four equivalent Sr(1), one Fe(1), and one Fe(2) atom. In the second O site, O(1) is bonded in a 4-coordinate geometry to two equivalent Sr(1), two equivalent Y(1), and two equivalent Fe(2) atoms. In the third O site, O(2) is bonded to two equivalent Y(1) and two equivalent Fe(2) atoms to form distorted corner-sharing OY2Fe2 tetrahedra. In the fourth O site, O(3) is bonded in a 6-coordinate geometry to two equivalent Sr(1), two equivalent Y(1), and two equivalent Fe(2) atoms. In the fifth O site, O(5) is bonded to four equivalent Sr(1) and two equivalent Fe(1) atoms to form face-sharing OSr4Fe2 octahedra. In the sixth O site, O(6) is bonded to four equivalent Sr(1) and two equivalent Fe(1) atoms to form a mixture of edge, face, and corner-sharing OSr4Fe2 octahedra. The corner-sharing octahedral tilt angles are 1°.
Sr4Y2(Fe2O5)3 crystallizes in the orthorhombic Fmmm space group. Sr(1) is bonded in a 10-coordinate geometry to one O(3), one O(5), two equivalent O(1), two equivalent O(6), and four equivalent O(4) atoms. The Sr(1)-O(3) bond length is 3.03 Å. The Sr(1)-O(5) bond length is 2.65 Å. Both Sr(1)-O(1) bond lengths are 3.17 Å. Both Sr(1)-O(6) bond lengths are 2.70 Å. There are two shorter (2.71 Å) and two longer (2.84 Å) Sr(1)-O(4) bond lengths. Y(1) is bonded in a body-centered cubic geometry to two equivalent O(2), two equivalent O(3), and four equivalent O(1) atoms. Both Y(1)-O(2) bond lengths are 2.33 Å. Both Y(1)-O(3) bond lengths are 2.52 Å. All Y(1)-O(1) bond lengths are 2.41 Å. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(5), two equivalent O(4), and two equivalent O(6) atoms to form corner-sharing FeO5 square pyramids. The Fe(1)-O(5) bond length is 1.95 Å. Both Fe(1)-O(4) bond lengths are 2.06 Å. Both Fe(1)-O(6) bond lengths are 1.97 Å. In the second Fe site, Fe(2) is bonded to one O(2), one O(3), one O(4), and two equivalent O(1) atoms to form distorted corner-sharing FeO5 trigonal bipyramids. The Fe(2)-O(2) bond length is 1.99 Å. The Fe(2)-O(3) bond length is 2.00 Å. The Fe(2)-O(4) bond length is 1.92 Å. Both Fe(2)-O(1) bond lengths are 2.02 Å. There are six inequivalent O sites. In the first O site, O(4) is bonded in a 6-coordinate geometry to four equivalent Sr(1), one Fe(1), and one Fe(2) atom. In the second O site, O(1) is bonded in a 4-coordinate geometry to two equivalent Sr(1), two equivalent Y(1), and two equivalent Fe(2) atoms. In the third O site, O(2) is bonded to two equivalent Y(1) and two equivalent Fe(2) atoms to form distorted corner-sharing OY2Fe2 tetrahedra. In the fourth O site, O(3) is bonded in a 6-coordinate geometry to two equivalent Sr(1), two equivalent Y(1), and two equivalent Fe(2) atoms. In the fifth O site, O(5) is bonded to four equivalent Sr(1) and two equivalent Fe(1) atoms to form face-sharing OSr4Fe2 octahedra. In the sixth O site, O(6) is bonded to four equivalent Sr(1) and two equivalent Fe(1) atoms to form a mixture of edge, face, and corner-sharing OSr4Fe2 octahedra. The corner-sharing octahedral tilt angles are 1°.