YFe3 crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Y sites. In the first Y site, Y(1) is bonded in a 12-coordinate geometry to three equivalent Fe(4) and nine equivalent Fe(1) atoms. In the second Y site, Y(2) is bonded in a 18-coordinate geometry to three equivalent Fe(2), three equivalent Fe(3), and twelve equivalent Fe(1) atoms. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent Y(2), three equivalent Y(1), one Fe(2), one Fe(3), one Fe(4), and four equivalent Fe(1) atoms to form FeY5Fe7 cuboctahedra that share corners with two equivalent Fe(4)Y6Fe6 cuboctahedra, corners with fifteen equivalent Fe(1)Y5Fe7 cuboctahedra, edges with eight equivalent Fe(1)Y5Fe7 cuboctahedra, faces with three equivalent Fe(4)Y6Fe6 cuboctahedra, and faces with eleven equivalent Fe(1)Y5Fe7 cuboctahedra. In the second Fe site, Fe(2) is bonded in a 9-coordinate geometry to three equivalent Y(2) and six equivalent Fe(1) atoms. In the third Fe site, Fe(3) is bonded in a 9-coordinate geometry to three equivalent Y(2) and six equivalent Fe(1) atoms. In the fourth Fe site, Fe(4) is bonded to six equivalent Y(1) and six equivalent Fe(1) atoms to form FeY6Fe6 cuboctahedra that share corners with twelve equivalent Fe(1)Y5Fe7 cuboctahedra, edges with six equivalent Fe(4)Y6Fe6 cuboctahedra, and faces with eighteen equivalent Fe(1)Y5Fe7 cuboctahedra.
YFe3 crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Y sites. In the first Y site, Y(1) is bonded in a 12-coordinate geometry to three equivalent Fe(4) and nine equivalent Fe(1) atoms. All Y(1)-Fe(4) bond lengths are 3.04 Å. There are six shorter (2.98 Å) and three longer (3.06 Å) Y(1)-Fe(1) bond lengths. In the second Y site, Y(2) is bonded in a 18-coordinate geometry to three equivalent Fe(2), three equivalent Fe(3), and twelve equivalent Fe(1) atoms. All Y(2)-Fe(2) bond lengths are 2.98 Å. All Y(2)-Fe(3) bond lengths are 2.98 Å. All Y(2)-Fe(1) bond lengths are 3.22 Å. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent Y(2), three equivalent Y(1), one Fe(2), one Fe(3), one Fe(4), and four equivalent Fe(1) atoms to form FeY5Fe7 cuboctahedra that share corners with two equivalent Fe(4)Y6Fe6 cuboctahedra, corners with fifteen equivalent Fe(1)Y5Fe7 cuboctahedra, edges with eight equivalent Fe(1)Y5Fe7 cuboctahedra, faces with three equivalent Fe(4)Y6Fe6 cuboctahedra, and faces with eleven equivalent Fe(1)Y5Fe7 cuboctahedra. The Fe(1)-Fe(2) bond length is 2.44 Å. The Fe(1)-Fe(3) bond length is 2.44 Å. The Fe(1)-Fe(4) bond length is 2.55 Å. There are two shorter (2.57 Å) and two longer (2.59 Å) Fe(1)-Fe(1) bond lengths. In the second Fe site, Fe(2) is bonded in a 9-coordinate geometry to three equivalent Y(2) and six equivalent Fe(1) atoms. In the third Fe site, Fe(3) is bonded in a 9-coordinate geometry to three equivalent Y(2) and six equivalent Fe(1) atoms. In the fourth Fe site, Fe(4) is bonded to six equivalent Y(1) and six equivalent Fe(1) atoms to form FeY6Fe6 cuboctahedra that share corners with twelve equivalent Fe(1)Y5Fe7 cuboctahedra, edges with six equivalent Fe(4)Y6Fe6 cuboctahedra, and faces with eighteen equivalent Fe(1)Y5Fe7 cuboctahedra.