BaCuO2 crystallizes in the orthorhombic P2_12_12 space group. Ba(1) is bonded in a distorted body-centered cubic geometry to four equivalent O(1) and four equivalent O(2) atoms. Cu(1) is bonded in a rectangular see-saw-like geometry to two equivalent O(1) and two equivalent O(2) atoms. There are two inequivalent O sites. In the first O site, O(1) is bonded in a 6-coordinate geometry to four equivalent Ba(1) and two equivalent Cu(1) atoms. In the second O site, O(2) is bonded to four equivalent Ba(1) and two equivalent Cu(1) atoms to form a mixture of corner, face, and edge-sharing OBa4Cu2 octahedra. The corner-sharing octahedral tilt angles are 58°.
BaCuO2 crystallizes in the orthorhombic P2_12_12 space group. Ba(1) is bonded in a distorted body-centered cubic geometry to four equivalent O(1) and four equivalent O(2) atoms. There are two shorter (2.87 Å) and two longer (2.98 Å) Ba(1)-O(1) bond lengths. There are three shorter (2.71 Å) and one longer (2.72 Å) Ba(1)-O(2) bond length. Cu(1) is bonded in a rectangular see-saw-like geometry to two equivalent O(1) and two equivalent O(2) atoms. There is one shorter (1.95 Å) and one longer (1.97 Å) Cu(1)-O(1) bond length. There is one shorter (2.05 Å) and one longer (2.07 Å) Cu(1)-O(2) bond length. There are two inequivalent O sites. In the first O site, O(1) is bonded in a 6-coordinate geometry to four equivalent Ba(1) and two equivalent Cu(1) atoms. In the second O site, O(2) is bonded to four equivalent Ba(1) and two equivalent Cu(1) atoms to form a mixture of corner, face, and edge-sharing OBa4Cu2 octahedra. The corner-sharing octahedral tilt angles are 58°.