Fe2CoO6 is Hydrophilite-derived structured and crystallizes in the trigonal P321 space group. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form FeO6 octahedra that share corners with four equivalent Co(1)O6 octahedra, corners with six equivalent Fe(2)O6 octahedra, and  an edgeedge with one Co(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 51-52°. In the second Fe site, Fe(2) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form FeO6 octahedra that share corners with two equivalent Co(2)O6 octahedra, corners with six equivalent Fe(1)O6 octahedra, and edges with two equivalent Co(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 51-53°. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded to three equivalent O(2) and three equivalent O(3) atoms to form CoO6 octahedra that share corners with six equivalent Fe(1)O6 octahedra and edges with three equivalent Fe(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 51-52°. In the second Co site, Co(2) is bonded to six equivalent O(1) atoms to form CoO6 octahedra that share corners with six equivalent Fe(2)O6 octahedra and edges with three equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles are 53°. There are three inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Fe(1), one Fe(2), and one Co(2) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(2), and one Co(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(2), and one Co(1) atom.
Fe2CoO6 is Hydrophilite-derived structured and crystallizes in the trigonal P321 space group. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form FeO6 octahedra that share corners with four equivalent Co(1)O6 octahedra, corners with six equivalent Fe(2)O6 octahedra, and  an edgeedge with one Co(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 51-52°. Both Fe(1)-O(1) bond lengths are 2.01 Å. Both Fe(1)-O(2) bond lengths are 2.02 Å. Both Fe(1)-O(3) bond lengths are 1.98 Å. In the second Fe site, Fe(2) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form FeO6 octahedra that share corners with two equivalent Co(2)O6 octahedra, corners with six equivalent Fe(1)O6 octahedra, and edges with two equivalent Co(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 51-53°. Both Fe(2)-O(1) bond lengths are 1.98 Å. Both Fe(2)-O(2) bond lengths are 1.94 Å. Both Fe(2)-O(3) bond lengths are 1.97 Å. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded to three equivalent O(2) and three equivalent O(3) atoms to form CoO6 octahedra that share corners with six equivalent Fe(1)O6 octahedra and edges with three equivalent Fe(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 51-52°. All Co(1)-O(2) bond lengths are 1.88 Å. All Co(1)-O(3) bond lengths are 1.87 Å. In the second Co site, Co(2) is bonded to six equivalent O(1) atoms to form CoO6 octahedra that share corners with six equivalent Fe(2)O6 octahedra and edges with three equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles are 53°. All Co(2)-O(1) bond lengths are 1.85 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Fe(1), one Fe(2), and one Co(2) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(2), and one Co(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(2), and one Co(1) atom.