FeMn2O4 is Spinel structured and crystallizes in the orthorhombic Imma space group. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form MnO6 octahedra that share corners with six equivalent Fe(1)O4 tetrahedra, edges with two equivalent Mn(1)O6 octahedra, and edges with four equivalent Mn(2)O6 octahedra. In the second Mn site, Mn(2) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form MnO6 octahedra that share corners with six equivalent Fe(1)O4 tetrahedra, edges with two equivalent Mn(2)O6 octahedra, and edges with four equivalent Mn(1)O6 octahedra. Fe(1) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form FeO4 tetrahedra that share corners with six equivalent Mn(1)O6 octahedra and corners with six equivalent Mn(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 55-58°. There are two inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Mn(1), two equivalent Mn(2), and one Fe(1) atom. In the second O site, O(2) is bonded in a rectangular see-saw-like geometry to one Mn(2), two equivalent Mn(1), and one Fe(1) atom.
FeMn2O4 is Spinel structured and crystallizes in the orthorhombic Imma space group. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form MnO6 octahedra that share corners with six equivalent Fe(1)O4 tetrahedra, edges with two equivalent Mn(1)O6 octahedra, and edges with four equivalent Mn(2)O6 octahedra. Both Mn(1)-O(1) bond lengths are 2.27 Å. All Mn(1)-O(2) bond lengths are 2.08 Å. In the second Mn site, Mn(2) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form MnO6 octahedra that share corners with six equivalent Fe(1)O4 tetrahedra, edges with two equivalent Mn(2)O6 octahedra, and edges with four equivalent Mn(1)O6 octahedra. Both Mn(2)-O(2) bond lengths are 2.28 Å. All Mn(2)-O(1) bond lengths are 2.03 Å. Fe(1) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form FeO4 tetrahedra that share corners with six equivalent Mn(1)O6 octahedra and corners with six equivalent Mn(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 55-58°. Both Fe(1)-O(1) bond lengths are 2.00 Å. Both Fe(1)-O(2) bond lengths are 1.90 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Mn(1), two equivalent Mn(2), and one Fe(1) atom. In the second O site, O(2) is bonded in a rectangular see-saw-like geometry to one Mn(2), two equivalent Mn(1), and one Fe(1) atom.