Ba2MnO4 is (La,Ba)CuO4 structured and crystallizes in the tetragonal I4/mmm space group. Ba(1) is bonded in a distorted q6 geometry to four equivalent O(1) and five equivalent O(2) atoms. Mn(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form corner-sharing MnO6 octahedra. The corner-sharing octahedra are not tilted. There are two inequivalent O sites. In the first O site, O(1) is bonded to four equivalent Ba(1) and two equivalent Mn(1) atoms to form distorted OBa4Mn2 octahedra that share corners with two equivalent O(1)Ba4Mn2 octahedra, corners with twelve equivalent O(2)Ba5Mn octahedra, edges with two equivalent O(1)Ba4Mn2 octahedra, faces with four equivalent O(1)Ba4Mn2 octahedra, and faces with four equivalent O(2)Ba5Mn octahedra. The corner-sharing octahedral tilt angles range from 0-58°. In the second O site, O(2) is bonded to five equivalent Ba(1) and one Mn(1) atom to form distorted OBa5Mn octahedra that share corners with five equivalent O(2)Ba5Mn octahedra, corners with twelve equivalent O(1)Ba4Mn2 octahedra, edges with eight equivalent O(2)Ba5Mn octahedra, and faces with four equivalent O(1)Ba4Mn2 octahedra. The corner-sharing octahedral tilt angles range from 0-58°.
Ba2MnO4 is (La,Ba)CuO4 structured and crystallizes in the tetragonal I4/mmm space group. Ba(1) is bonded in a distorted q6 geometry to four equivalent O(1) and five equivalent O(2) atoms. All Ba(1)-O(1) bond lengths are 2.77 Å. There is one shorter (2.79 Å) and four longer (2.87 Å) Ba(1)-O(2) bond lengths. Mn(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form corner-sharing MnO6 octahedra. The corner-sharing octahedra are not tilted. Both Mn(1)-O(2) bond lengths are 1.97 Å. All Mn(1)-O(1) bond lengths are 2.03 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded to four equivalent Ba(1) and two equivalent Mn(1) atoms to form distorted OBa4Mn2 octahedra that share corners with two equivalent O(1)Ba4Mn2 octahedra, corners with twelve equivalent O(2)Ba5Mn octahedra, edges with two equivalent O(1)Ba4Mn2 octahedra, faces with four equivalent O(1)Ba4Mn2 octahedra, and faces with four equivalent O(2)Ba5Mn octahedra. The corner-sharing octahedral tilt angles range from 0-58°. In the second O site, O(2) is bonded to five equivalent Ba(1) and one Mn(1) atom to form distorted OBa5Mn octahedra that share corners with five equivalent O(2)Ba5Mn octahedra, corners with twelve equivalent O(1)Ba4Mn2 octahedra, edges with eight equivalent O(2)Ba5Mn octahedra, and faces with four equivalent O(1)Ba4Mn2 octahedra. The corner-sharing octahedral tilt angles range from 0-58°.