Ca2FeMoO6 crystallizes in the monoclinic P2_1/c space group. Ca(1) is bonded in a 8-coordinate geometry to two equivalent O(3), three equivalent O(1), and three equivalent O(2) atoms. Mo(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form MoO6 octahedra that share corners with six equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 30-31°. 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 six equivalent Mo(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 30-31°. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to three equivalent Ca(1), one Mo(1), and one Fe(1) atom. In the second O site, O(2) is bonded in a 5-coordinate geometry to three equivalent Ca(1), one Mo(1), and one Fe(1) atom. In the third O site, O(3) is bonded to two equivalent Ca(1), one Mo(1), and one Fe(1) atom to form distorted corner-sharing OCa2FeMo tetrahedra.
Ca2FeMoO6 crystallizes in the monoclinic P2_1/c space group. Ca(1) is bonded in a 8-coordinate geometry to two equivalent O(3), three equivalent O(1), and three equivalent O(2) atoms. There is one shorter (2.34 Å) and one longer (2.41 Å) Ca(1)-O(3) bond length. There are a spread of Ca(1)-O(1) bond distances ranging from 2.35-2.71 Å. There are a spread of Ca(1)-O(2) bond distances ranging from 2.40-2.78 Å. Mo(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form MoO6 octahedra that share corners with six equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 30-31°. Both Mo(1)-O(1) bond lengths are 2.04 Å. Both Mo(1)-O(2) bond lengths are 1.95 Å. Both Mo(1)-O(3) bond lengths are 2.04 Å. 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 six equivalent Mo(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 30-31°. Both Fe(1)-O(1) bond lengths are 2.01 Å. Both Fe(1)-O(2) bond lengths are 2.10 Å. Both Fe(1)-O(3) bond lengths are 2.02 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to three equivalent Ca(1), one Mo(1), and one Fe(1) atom. In the second O site, O(2) is bonded in a 5-coordinate geometry to three equivalent Ca(1), one Mo(1), and one Fe(1) atom. In the third O site, O(3) is bonded to two equivalent Ca(1), one Mo(1), and one Fe(1) atom to form distorted corner-sharing OCa2FeMo tetrahedra.