Ca2MnO4 is (La,Ba)CuO4-like structured and crystallizes in the tetragonal I4_1/acd space group. Ca(1) is bonded in a 9-coordinate geometry to four equivalent O(2) and five equivalent O(1) atoms. Mn(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form corner-sharing MnO6 octahedra. The corner-sharing octahedral tilt angles are 19°. There are two inequivalent O sites. In the first O site, O(2) is bonded in a 4-coordinate geometry to four equivalent Ca(1) and two equivalent Mn(1) atoms. In the second O site, O(1) is bonded to five equivalent Ca(1) and one Mn(1) atom to form a mixture of corner and edge-sharing OCa5Mn octahedra. The corner-sharing octahedral tilt angles range from 0-7°.
Ca2MnO4 is (La,Ba)CuO4-like structured and crystallizes in the tetragonal I4_1/acd space group. Ca(1) is bonded in a 9-coordinate geometry to four equivalent O(2) and five equivalent O(1) atoms. There are two shorter (2.35 Å) and two longer (2.79 Å) Ca(1)-O(2) bond lengths. There is one shorter (2.31 Å) and four longer (2.59 Å) Ca(1)-O(1) bond lengths. Mn(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form corner-sharing MnO6 octahedra. The corner-sharing octahedral tilt angles are 19°. Both Mn(1)-O(1) bond lengths are 1.95 Å. All Mn(1)-O(2) bond lengths are 1.85 Å. There are two inequivalent O sites. In the first O site, O(2) is bonded in a 4-coordinate geometry to four equivalent Ca(1) and two equivalent Mn(1) atoms. In the second O site, O(1) is bonded to five equivalent Ca(1) and one Mn(1) atom to form a mixture of corner and edge-sharing OCa5Mn octahedra. The corner-sharing octahedral tilt angles range from 0-7°.