ZnFeO2 crystallizes in the triclinic P-1 space group. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(2), one O(3), and two equivalent O(1) atoms to form distorted FeO4 trigonal pyramids that share corners with four equivalent Zn(1)O4 tetrahedra, corners with four equivalent Fe(2)O5 trigonal bipyramids, and corners with two equivalent Fe(1)O4 trigonal pyramids. In the second Fe site, Fe(2) is bonded to one O(1), two equivalent O(2), and two equivalent O(4) atoms to form distorted FeO5 trigonal bipyramids that share  a cornercorner with one Zn(1)O4 tetrahedra, corners with four equivalent Fe(1)O4 trigonal pyramids,  an edgeedge with one Zn(1)O4 tetrahedra, and edges with two equivalent Fe(2)O5 trigonal bipyramids. There are two inequivalent Zn sites. In the first Zn site, Zn(1) is bonded to one O(1), one O(4), and two equivalent O(3) atoms to form distorted ZnO4 tetrahedra that share corners with two equivalent Zn(1)O4 tetrahedra,  a cornercorner with one Fe(2)O5 trigonal bipyramid, corners with four equivalent Fe(1)O4 trigonal pyramids, and  an edgeedge with one Fe(2)O5 trigonal bipyramid. In the second Zn site, Zn(2) is bonded in a rectangular see-saw-like geometry to one O(3), one O(4), and two equivalent O(2) atoms. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Fe(2), two equivalent Fe(1), and one Zn(1) atom to form distorted OZnFe3 tetrahedra that share corners with two equivalent O(1)ZnFe3 tetrahedra, corners with four equivalent O(2)Zn2Fe3 trigonal bipyramids,  a cornercorner with one O(4)Zn2Fe2 trigonal pyramid, corners with four equivalent O(3)Zn3Fe trigonal pyramids, and  an edgeedge with one O(4)Zn2Fe2 trigonal pyramid. In the second O site, O(2) is bonded to one Fe(1), two equivalent Fe(2), and two equivalent Zn(2) atoms to form distorted OZn2Fe3 trigonal bipyramids that share corners with four equivalent O(1)ZnFe3 tetrahedra,  a cornercorner with one O(3)Zn3Fe trigonal pyramid, corners with four equivalent O(4)Zn2Fe2 trigonal pyramids, edges with two equivalent O(2)Zn2Fe3 trigonal bipyramids,  an edgeedge with one O(4)Zn2Fe2 trigonal pyramid, and  an edgeedge with one O(3)Zn3Fe trigonal pyramid. In the third O site, O(3) is bonded to one Fe(1), one Zn(2), and two equivalent Zn(1) atoms to form distorted OZn3Fe trigonal pyramids that share corners with four equivalent O(1)ZnFe3 tetrahedra,  a cornercorner with one O(2)Zn2Fe3 trigonal bipyramid, corners with two equivalent O(3)Zn3Fe trigonal pyramids, corners with three equivalent O(4)Zn2Fe2 trigonal pyramids, and  an edgeedge with one O(2)Zn2Fe3 trigonal bipyramid. In the fourth O site, O(4) is bonded to two equivalent Fe(2), one Zn(1), and one Zn(2) atom to form distorted OZn2Fe2 trigonal pyramids that share  a cornercorner with one O(1)ZnFe3 tetrahedra, corners with four equivalent O(2)Zn2Fe3 trigonal bipyramids, corners with two equivalent O(4)Zn2Fe2 trigonal pyramids, corners with three equivalent O(3)Zn3Fe trigonal pyramids,  an edgeedge with one O(1)ZnFe3 tetrahedra, and  an edgeedge with one O(2)Zn2Fe3 trigonal bipyramid.
ZnFeO2 crystallizes in the triclinic P-1 space group. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(2), one O(3), and two equivalent O(1) atoms to form distorted FeO4 trigonal pyramids that share corners with four equivalent Zn(1)O4 tetrahedra, corners with four equivalent Fe(2)O5 trigonal bipyramids, and corners with two equivalent Fe(1)O4 trigonal pyramids. The Fe(1)-O(2) bond length is 2.11 Å. The Fe(1)-O(3) bond length is 2.11 Å. There is one shorter (1.99 Å) and one longer (2.00 Å) Fe(1)-O(1) bond length. In the second Fe site, Fe(2) is bonded to one O(1), two equivalent O(2), and two equivalent O(4) atoms to form distorted FeO5 trigonal bipyramids that share  a cornercorner with one Zn(1)O4 tetrahedra, corners with four equivalent Fe(1)O4 trigonal pyramids,  an edgeedge with one Zn(1)O4 tetrahedra, and edges with two equivalent Fe(2)O5 trigonal bipyramids. The Fe(2)-O(1) bond length is 2.15 Å. There is one shorter (2.15 Å) and one longer (2.25 Å) Fe(2)-O(2) bond length. There is one shorter (2.06 Å) and one longer (2.17 Å) Fe(2)-O(4) bond length. There are two inequivalent Zn sites. In the first Zn site, Zn(1) is bonded to one O(1), one O(4), and two equivalent O(3) atoms to form distorted ZnO4 tetrahedra that share corners with two equivalent Zn(1)O4 tetrahedra,  a cornercorner with one Fe(2)O5 trigonal bipyramid, corners with four equivalent Fe(1)O4 trigonal pyramids, and  an edgeedge with one Fe(2)O5 trigonal bipyramid. The Zn(1)-O(1) bond length is 2.04 Å. The Zn(1)-O(4) bond length is 2.00 Å. There is one shorter (1.98 Å) and one longer (2.00 Å) Zn(1)-O(3) bond length. In the second Zn site, Zn(2) is bonded in a rectangular see-saw-like geometry to one O(3), one O(4), and two equivalent O(2) atoms. The Zn(2)-O(3) bond length is 1.96 Å. The Zn(2)-O(4) bond length is 1.89 Å. There is one shorter (2.11 Å) and one longer (2.17 Å) Zn(2)-O(2) bond length. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Fe(2), two equivalent Fe(1), and one Zn(1) atom to form distorted OZnFe3 tetrahedra that share corners with two equivalent O(1)ZnFe3 tetrahedra, corners with four equivalent O(2)Zn2Fe3 trigonal bipyramids,  a cornercorner with one O(4)Zn2Fe2 trigonal pyramid, corners with four equivalent O(3)Zn3Fe trigonal pyramids, and  an edgeedge with one O(4)Zn2Fe2 trigonal pyramid. In the second O site, O(2) is bonded to one Fe(1), two equivalent Fe(2), and two equivalent Zn(2) atoms to form distorted OZn2Fe3 trigonal bipyramids that share corners with four equivalent O(1)ZnFe3 tetrahedra,  a cornercorner with one O(3)Zn3Fe trigonal pyramid, corners with four equivalent O(4)Zn2Fe2 trigonal pyramids, edges with two equivalent O(2)Zn2Fe3 trigonal bipyramids,  an edgeedge with one O(4)Zn2Fe2 trigonal pyramid, and  an edgeedge with one O(3)Zn3Fe trigonal pyramid. In the third O site, O(3) is bonded to one Fe(1), one Zn(2), and two equivalent Zn(1) atoms to form distorted OZn3Fe trigonal pyramids that share corners with four equivalent O(1)ZnFe3 tetrahedra,  a cornercorner with one O(2)Zn2Fe3 trigonal bipyramid, corners with two equivalent O(3)Zn3Fe trigonal pyramids, corners with three equivalent O(4)Zn2Fe2 trigonal pyramids, and  an edgeedge with one O(2)Zn2Fe3 trigonal bipyramid. In the fourth O site, O(4) is bonded to two equivalent Fe(2), one Zn(1), and one Zn(2) atom to form distorted OZn2Fe2 trigonal pyramids that share  a cornercorner with one O(1)ZnFe3 tetrahedra, corners with four equivalent O(2)Zn2Fe3 trigonal bipyramids, corners with two equivalent O(4)Zn2Fe2 trigonal pyramids, corners with three equivalent O(3)Zn3Fe trigonal pyramids,  an edgeedge with one O(1)ZnFe3 tetrahedra, and  an edgeedge with one O(2)Zn2Fe3 trigonal bipyramid.