Fe2CoO6 is Hydrophilite-derived structured and crystallizes in the tetragonal P4_2/mnm space group. Fe(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form FeO6 octahedra that share corners with four equivalent Fe(1)O6 octahedra, corners with four equivalent Co(1)O6 octahedra,  an edgeedge with one Fe(1)O6 octahedra, and  an edgeedge with one Co(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 49-53°. Co(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form CoO6 octahedra that share corners with eight equivalent Fe(1)O6 octahedra and edges with two equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 49-50°. There are two inequivalent O sites. In the first O site, O(2) is bonded in a distorted trigonal planar geometry to two equivalent Fe(1) and one Co(1) atom. In the second O site, O(1) is bonded in a trigonal planar geometry to two equivalent Fe(1) and one Co(1) atom.
Fe2CoO6 is Hydrophilite-derived structured and crystallizes in the tetragonal P4_2/mnm space group. Fe(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form FeO6 octahedra that share corners with four equivalent Fe(1)O6 octahedra, corners with four equivalent Co(1)O6 octahedra,  an edgeedge with one Fe(1)O6 octahedra, and  an edgeedge with one Co(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 49-53°. Both Fe(1)-O(2) bond lengths are 1.97 Å. There are two shorter (1.94 Å) and two longer (1.97 Å) Fe(1)-O(1) bond lengths. Co(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form CoO6 octahedra that share corners with eight equivalent Fe(1)O6 octahedra and edges with two equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 49-50°. Both Co(1)-O(2) bond lengths are 1.88 Å. All Co(1)-O(1) bond lengths are 1.89 Å. There are two inequivalent O sites. In the first O site, O(2) is bonded in a distorted trigonal planar geometry to two equivalent Fe(1) and one Co(1) atom. In the second O site, O(1) is bonded in a trigonal planar geometry to two equivalent Fe(1) and one Co(1) atom.