Ba2IrO4 is (La,Ba)CuO4 structured and crystallizes in the tetragonal I4/mmm space group. Ba(1) is bonded in a 9-coordinate geometry to four equivalent O(1) and five equivalent O(2) atoms. Ir(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form corner-sharing IrO6 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 Ir(1) atoms to form distorted OBa4Ir2 octahedra that share corners with two equivalent O(1)Ba4Ir2 octahedra, corners with twelve equivalent O(2)Ba5Ir octahedra, edges with two equivalent O(1)Ba4Ir2 octahedra, faces with four equivalent O(1)Ba4Ir2 octahedra, and faces with four equivalent O(2)Ba5Ir octahedra. The corner-sharing octahedral tilt angles range from 0-57°. In the second O site, O(2) is bonded to five equivalent Ba(1) and one Ir(1) atom to form OBa5Ir octahedra that share corners with five equivalent O(2)Ba5Ir octahedra, corners with twelve equivalent O(1)Ba4Ir2 octahedra, edges with eight equivalent O(2)Ba5Ir octahedra, and faces with four equivalent O(1)Ba4Ir2 octahedra. The corner-sharing octahedral tilt angles range from 0-57°.
Ba2IrO4 is (La,Ba)CuO4 structured and crystallizes in the tetragonal I4/mmm space group. Ba(1) is bonded in a 9-coordinate geometry to four equivalent O(1) and five equivalent O(2) atoms. All Ba(1)-O(1) bond lengths are 2.80 Å. There is one shorter (2.70 Å) and four longer (2.85 Å) Ba(1)-O(2) bond lengths. Ir(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form corner-sharing IrO6 octahedra. The corner-sharing octahedra are not tilted. Both Ir(1)-O(2) bond lengths are 2.07 Å. All Ir(1)-O(1) bond lengths are 2.02 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded to four equivalent Ba(1) and two equivalent Ir(1) atoms to form distorted OBa4Ir2 octahedra that share corners with two equivalent O(1)Ba4Ir2 octahedra, corners with twelve equivalent O(2)Ba5Ir octahedra, edges with two equivalent O(1)Ba4Ir2 octahedra, faces with four equivalent O(1)Ba4Ir2 octahedra, and faces with four equivalent O(2)Ba5Ir octahedra. The corner-sharing octahedral tilt angles range from 0-57°. In the second O site, O(2) is bonded to five equivalent Ba(1) and one Ir(1) atom to form OBa5Ir octahedra that share corners with five equivalent O(2)Ba5Ir octahedra, corners with twelve equivalent O(1)Ba4Ir2 octahedra, edges with eight equivalent O(2)Ba5Ir octahedra, and faces with four equivalent O(1)Ba4Ir2 octahedra. The corner-sharing octahedral tilt angles range from 0-57°.