Y(FeS2)2 is Spinel-like structured and crystallizes in the monoclinic C2/c space group. Y(1) is bonded to two equivalent S(1) and four equivalent S(2) atoms to form YS6 octahedra that share corners with six equivalent Fe(1)S4 tetrahedra, edges with two equivalent Y(1)S6 octahedra, and edges with four equivalent Fe(2)S6 octahedra. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent S(1) and two equivalent S(2) atoms to form FeS4 tetrahedra that share corners with six equivalent Y(1)S6 octahedra and corners with six equivalent Fe(2)S6 octahedra. The corner-sharing octahedral tilt angles range from 46-66°. In the second Fe site, Fe(2) is bonded to two equivalent S(2) and four equivalent S(1) atoms to form FeS6 octahedra that share corners with six equivalent Fe(1)S4 tetrahedra, edges with two equivalent Fe(2)S6 octahedra, and edges with four equivalent Y(1)S6 octahedra. There are two inequivalent S sites. In the first S site, S(1) is bonded in a rectangular see-saw-like geometry to one Y(1), one Fe(1), and two equivalent Fe(2) atoms. In the second S site, S(2) is bonded in a rectangular see-saw-like geometry to two equivalent Y(1), one Fe(1), and one Fe(2) atom.
Y(FeS2)2 is Spinel-like structured and crystallizes in the monoclinic C2/c space group. Y(1) is bonded to two equivalent S(1) and four equivalent S(2) atoms to form YS6 octahedra that share corners with six equivalent Fe(1)S4 tetrahedra, edges with two equivalent Y(1)S6 octahedra, and edges with four equivalent Fe(2)S6 octahedra. Both Y(1)-S(1) bond lengths are 2.68 Å. All Y(1)-S(2) bond lengths are 2.68 Å. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent S(1) and two equivalent S(2) atoms to form FeS4 tetrahedra that share corners with six equivalent Y(1)S6 octahedra and corners with six equivalent Fe(2)S6 octahedra. The corner-sharing octahedral tilt angles range from 46-66°. Both Fe(1)-S(1) bond lengths are 2.35 Å. Both Fe(1)-S(2) bond lengths are 2.27 Å. In the second Fe site, Fe(2) is bonded to two equivalent S(2) and four equivalent S(1) atoms to form FeS6 octahedra that share corners with six equivalent Fe(1)S4 tetrahedra, edges with two equivalent Fe(2)S6 octahedra, and edges with four equivalent Y(1)S6 octahedra. Both Fe(2)-S(2) bond lengths are 2.34 Å. There are two shorter (2.45 Å) and two longer (2.48 Å) Fe(2)-S(1) bond lengths. There are two inequivalent S sites. In the first S site, S(1) is bonded in a rectangular see-saw-like geometry to one Y(1), one Fe(1), and two equivalent Fe(2) atoms. In the second S site, S(2) is bonded in a rectangular see-saw-like geometry to two equivalent Y(1), one Fe(1), and one Fe(2) atom.