Y(FeO2)3 is beta indium sulfide-derived structured and crystallizes in the trigonal P-3m1 space group. There are two inequivalent Y sites. In the first Y site, Y(1) is bonded to one O(1) and three equivalent O(4) atoms to form YO4 tetrahedra that share corners with three equivalent Fe(3)O6 octahedra and corners with nine equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 51-67°. In the second Y site, Y(2) is bonded to one O(2) and three equivalent O(6) atoms to form YO4 tetrahedra that share corners with three equivalent Fe(1)O6 octahedra, corners with three equivalent Fe(4)O6 octahedra, and corners with six equivalent Fe(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 59-63°. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(2), two equivalent O(4), and two equivalent O(5) atoms to form FeO6 octahedra that share  a cornercorner with one Y(2)O4 tetrahedra, corners with three equivalent Y(1)O4 tetrahedra,  an edgeedge with one Fe(3)O6 octahedra,  an edgeedge with one Fe(4)O6 octahedra, and edges with four equivalent Fe(1)O6 octahedra. In the second Fe site, Fe(2) is bonded to two equivalent O(3) and four equivalent O(6) atoms to form FeO6 octahedra that share corners with four equivalent Y(2)O4 tetrahedra, edges with two equivalent Fe(4)O6 octahedra, and edges with four equivalent Fe(2)O6 octahedra. In the third Fe site, Fe(3) is bonded to six equivalent O(4) atoms to form FeO6 octahedra that share corners with six equivalent Y(1)O4 tetrahedra and edges with six equivalent Fe(1)O6 octahedra. In the fourth Fe site, Fe(4) is bonded to three equivalent O(5) and three equivalent O(6) atoms to form FeO6 octahedra that share corners with three equivalent Y(2)O4 tetrahedra, edges with three equivalent Fe(1)O6 octahedra, and edges with three equivalent Fe(2)O6 octahedra. There are six inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Y(1) and three equivalent Fe(1) atoms. In the second O site, O(2) is bonded to one Y(2) and three equivalent Fe(1) atoms to form a mixture of edge and corner-sharing OYFe3 tetrahedra. In the third O site, O(3) is bonded in a trigonal non-coplanar geometry to three equivalent Fe(2) atoms. In the fourth O site, O(4) is bonded to one Y(1), one Fe(3), and two equivalent Fe(1) atoms to form a mixture of edge and corner-sharing OYFe3 tetrahedra. In the fifth O site, O(5) is bonded in a distorted T-shaped geometry to one Fe(4) and two equivalent Fe(1) atoms. In the sixth O site, O(6) is bonded to one Y(2), one Fe(4), and two equivalent Fe(2) atoms to form a mixture of distorted edge and corner-sharing OYFe3 tetrahedra.
Y(FeO2)3 is beta indium sulfide-derived structured and crystallizes in the trigonal P-3m1 space group. There are two inequivalent Y sites. In the first Y site, Y(1) is bonded to one O(1) and three equivalent O(4) atoms to form YO4 tetrahedra that share corners with three equivalent Fe(3)O6 octahedra and corners with nine equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 51-67°. The Y(1)-O(1) bond length is 2.19 Å. All Y(1)-O(4) bond lengths are 2.11 Å. In the second Y site, Y(2) is bonded to one O(2) and three equivalent O(6) atoms to form YO4 tetrahedra that share corners with three equivalent Fe(1)O6 octahedra, corners with three equivalent Fe(4)O6 octahedra, and corners with six equivalent Fe(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 59-63°. The Y(2)-O(2) bond length is 2.12 Å. All Y(2)-O(6) bond lengths are 2.15 Å. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(2), two equivalent O(4), and two equivalent O(5) atoms to form FeO6 octahedra that share  a cornercorner with one Y(2)O4 tetrahedra, corners with three equivalent Y(1)O4 tetrahedra,  an edgeedge with one Fe(3)O6 octahedra,  an edgeedge with one Fe(4)O6 octahedra, and edges with four equivalent Fe(1)O6 octahedra. The Fe(1)-O(1) bond length is 2.15 Å. The Fe(1)-O(2) bond length is 2.09 Å. Both Fe(1)-O(4) bond lengths are 2.11 Å. Both Fe(1)-O(5) bond lengths are 1.98 Å. In the second Fe site, Fe(2) is bonded to two equivalent O(3) and four equivalent O(6) atoms to form FeO6 octahedra that share corners with four equivalent Y(2)O4 tetrahedra, edges with two equivalent Fe(4)O6 octahedra, and edges with four equivalent Fe(2)O6 octahedra. Both Fe(2)-O(3) bond lengths are 2.03 Å. All Fe(2)-O(6) bond lengths are 2.11 Å. In the third Fe site, Fe(3) is bonded to six equivalent O(4) atoms to form FeO6 octahedra that share corners with six equivalent Y(1)O4 tetrahedra and edges with six equivalent Fe(1)O6 octahedra. All Fe(3)-O(4) bond lengths are 2.03 Å. In the fourth Fe site, Fe(4) is bonded to three equivalent O(5) and three equivalent O(6) atoms to form FeO6 octahedra that share corners with three equivalent Y(2)O4 tetrahedra, edges with three equivalent Fe(1)O6 octahedra, and edges with three equivalent Fe(2)O6 octahedra. All Fe(4)-O(5) bond lengths are 2.09 Å. All Fe(4)-O(6) bond lengths are 2.12 Å. There are six inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Y(1) and three equivalent Fe(1) atoms. In the second O site, O(2) is bonded to one Y(2) and three equivalent Fe(1) atoms to form a mixture of edge and corner-sharing OYFe3 tetrahedra. In the third O site, O(3) is bonded in a trigonal non-coplanar geometry to three equivalent Fe(2) atoms. In the fourth O site, O(4) is bonded to one Y(1), one Fe(3), and two equivalent Fe(1) atoms to form a mixture of edge and corner-sharing OYFe3 tetrahedra. In the fifth O site, O(5) is bonded in a distorted T-shaped geometry to one Fe(4) and two equivalent Fe(1) atoms. In the sixth O site, O(6) is bonded to one Y(2), one Fe(4), and two equivalent Fe(2) atoms to form a mixture of distorted edge and corner-sharing OYFe3 tetrahedra.