YFe2O4 is Aluminum carbonitride-like structured and crystallizes in the triclinic P-1 space group. Y(1) is bonded to three equivalent O(3) and three equivalent O(4) atoms to form distorted YO6 octahedra that share corners with three equivalent Fe(1)O5 trigonal bipyramids, corners with three equivalent Fe(2)O5 trigonal bipyramids, and edges with six equivalent Y(1)O6 octahedra. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(3), two equivalent O(1), and two equivalent O(2) atoms to form FeO5 trigonal bipyramids that share corners with three equivalent Y(1)O6 octahedra, corners with two equivalent Fe(1)O5 trigonal bipyramids, corners with four equivalent Fe(2)O5 trigonal bipyramids,  an edgeedge with one Fe(1)O5 trigonal bipyramid, and edges with two equivalent Fe(2)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 55-66°. In the second Fe site, Fe(2) is bonded to one O(4), two equivalent O(1), and two equivalent O(2) atoms to form FeO5 trigonal bipyramids that share corners with three equivalent Y(1)O6 octahedra, corners with two equivalent Fe(2)O5 trigonal bipyramids, corners with four equivalent Fe(1)O5 trigonal bipyramids,  an edgeedge with one Fe(2)O5 trigonal bipyramid, and edges with two equivalent Fe(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 59-69°. There are four inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Fe(1) and two equivalent Fe(2) atoms to form OFe4 trigonal pyramids that share corners with two equivalent O(3)Y3Fe tetrahedra, corners with two equivalent O(4)Y3Fe tetrahedra, corners with two equivalent O(1)Fe4 trigonal pyramids, corners with four equivalent O(2)Fe4 trigonal pyramids,  an edgeedge with one O(1)Fe4 trigonal pyramid, and edges with two equivalent O(2)Fe4 trigonal pyramids. In the second O site, O(2) is bonded to two equivalent Fe(1) and two equivalent Fe(2) atoms to form distorted OFe4 trigonal pyramids that share corners with two equivalent O(3)Y3Fe tetrahedra, corners with two equivalent O(4)Y3Fe tetrahedra, corners with two equivalent O(2)Fe4 trigonal pyramids, corners with four equivalent O(1)Fe4 trigonal pyramids,  an edgeedge with one O(2)Fe4 trigonal pyramid, and edges with two equivalent O(1)Fe4 trigonal pyramids. In the third O site, O(3) is bonded to three equivalent Y(1) and one Fe(1) atom to form distorted OY3Fe tetrahedra that share corners with two equivalent O(3)Y3Fe tetrahedra, corners with seven equivalent O(4)Y3Fe tetrahedra, corners with two equivalent O(1)Fe4 trigonal pyramids, corners with two equivalent O(2)Fe4 trigonal pyramids,  an edgeedge with one O(4)Y3Fe tetrahedra, and edges with two equivalent O(3)Y3Fe tetrahedra. In the fourth O site, O(4) is bonded to three equivalent Y(1) and one Fe(2) atom to form OY3Fe tetrahedra that share corners with two equivalent O(4)Y3Fe tetrahedra, corners with seven equivalent O(3)Y3Fe tetrahedra, corners with two equivalent O(1)Fe4 trigonal pyramids, corners with two equivalent O(2)Fe4 trigonal pyramids,  an edgeedge with one O(3)Y3Fe tetrahedra, and edges with two equivalent O(4)Y3Fe tetrahedra.
YFe2O4 is Aluminum carbonitride-like structured and crystallizes in the triclinic P-1 space group. Y(1) is bonded to three equivalent O(3) and three equivalent O(4) atoms to form distorted YO6 octahedra that share corners with three equivalent Fe(1)O5 trigonal bipyramids, corners with three equivalent Fe(2)O5 trigonal bipyramids, and edges with six equivalent Y(1)O6 octahedra. There are a spread of Y(1)-O(3) bond distances ranging from 2.30-2.34 Å. There is one shorter (2.26 Å) and two longer (2.28 Å) Y(1)-O(4) bond lengths. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(3), two equivalent O(1), and two equivalent O(2) atoms to form FeO5 trigonal bipyramids that share corners with three equivalent Y(1)O6 octahedra, corners with two equivalent Fe(1)O5 trigonal bipyramids, corners with four equivalent Fe(2)O5 trigonal bipyramids,  an edgeedge with one Fe(1)O5 trigonal bipyramid, and edges with two equivalent Fe(2)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 55-66°. The Fe(1)-O(3) bond length is 1.94 Å. There is one shorter (1.97 Å) and one longer (2.08 Å) Fe(1)-O(1) bond length. Both Fe(1)-O(2) bond lengths are 2.02 Å. In the second Fe site, Fe(2) is bonded to one O(4), two equivalent O(1), and two equivalent O(2) atoms to form FeO5 trigonal bipyramids that share corners with three equivalent Y(1)O6 octahedra, corners with two equivalent Fe(2)O5 trigonal bipyramids, corners with four equivalent Fe(1)O5 trigonal bipyramids,  an edgeedge with one Fe(2)O5 trigonal bipyramid, and edges with two equivalent Fe(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 59-69°. The Fe(2)-O(4) bond length is 2.04 Å. There is one shorter (2.05 Å) and one longer (2.11 Å) Fe(2)-O(1) bond length. There is one shorter (2.11 Å) and one longer (2.32 Å) Fe(2)-O(2) bond length. There are four inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Fe(1) and two equivalent Fe(2) atoms to form OFe4 trigonal pyramids that share corners with two equivalent O(3)Y3Fe tetrahedra, corners with two equivalent O(4)Y3Fe tetrahedra, corners with two equivalent O(1)Fe4 trigonal pyramids, corners with four equivalent O(2)Fe4 trigonal pyramids,  an edgeedge with one O(1)Fe4 trigonal pyramid, and edges with two equivalent O(2)Fe4 trigonal pyramids. In the second O site, O(2) is bonded to two equivalent Fe(1) and two equivalent Fe(2) atoms to form distorted OFe4 trigonal pyramids that share corners with two equivalent O(3)Y3Fe tetrahedra, corners with two equivalent O(4)Y3Fe tetrahedra, corners with two equivalent O(2)Fe4 trigonal pyramids, corners with four equivalent O(1)Fe4 trigonal pyramids,  an edgeedge with one O(2)Fe4 trigonal pyramid, and edges with two equivalent O(1)Fe4 trigonal pyramids. In the third O site, O(3) is bonded to three equivalent Y(1) and one Fe(1) atom to form distorted OY3Fe tetrahedra that share corners with two equivalent O(3)Y3Fe tetrahedra, corners with seven equivalent O(4)Y3Fe tetrahedra, corners with two equivalent O(1)Fe4 trigonal pyramids, corners with two equivalent O(2)Fe4 trigonal pyramids,  an edgeedge with one O(4)Y3Fe tetrahedra, and edges with two equivalent O(3)Y3Fe tetrahedra. In the fourth O site, O(4) is bonded to three equivalent Y(1) and one Fe(2) atom to form OY3Fe tetrahedra that share corners with two equivalent O(4)Y3Fe tetrahedra, corners with seven equivalent O(3)Y3Fe tetrahedra, corners with two equivalent O(1)Fe4 trigonal pyramids, corners with two equivalent O(2)Fe4 trigonal pyramids,  an edgeedge with one O(3)Y3Fe tetrahedra, and edges with two equivalent O(4)Y3Fe tetrahedra.