Ba4As2O is (La,Ba)CuO4 structured and crystallizes in the tetragonal I4/mmm space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 6-coordinate geometry to five equivalent As(1) and one O(1) atom. In the second Ba site, Ba(2) is bonded in a distorted linear geometry to four equivalent As(1) and two equivalent O(1) atoms. As(1) is bonded in a 9-coordinate geometry to four equivalent Ba(2) and five equivalent Ba(1) atoms. O(1) is bonded to two equivalent Ba(1) and four equivalent Ba(2) atoms to form corner-sharing OBa6 octahedra. The corner-sharing octahedra are not tilted.
Ba4As2O is (La,Ba)CuO4 structured and crystallizes in the tetragonal I4/mmm space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 6-coordinate geometry to five equivalent As(1) and one O(1) atom. There is one shorter (3.29 Å) and four longer (3.74 Å) Ba(1)-As(1) bond lengths. The Ba(1)-O(1) bond length is 3.05 Å. In the second Ba site, Ba(2) is bonded in a distorted linear geometry to four equivalent As(1) and two equivalent O(1) atoms. All Ba(2)-As(1) bond lengths are 3.51 Å. Both Ba(2)-O(1) bond lengths are 2.60 Å. As(1) is bonded in a 9-coordinate geometry to four equivalent Ba(2) and five equivalent Ba(1) atoms. O(1) is bonded to two equivalent Ba(1) and four equivalent Ba(2) atoms to form corner-sharing OBa6 octahedra. The corner-sharing octahedra are not tilted.