BaCrCuAlO5 crystallizes in the tetragonal P4mm space group. Ba(1) is bonded in a 8-coordinate geometry to four equivalent O(2) and four equivalent O(3) atoms. Cr(1) is bonded to one O(3) and four equivalent O(1) atoms to form distorted corner-sharing CrO5 trigonal bipyramids. Cu(1) is bonded in a distorted square co-planar geometry to four equivalent O(2) atoms. Al(1) is bonded in a body-centered cubic geometry to four equivalent O(1) and four equivalent O(2) atoms. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted see-saw-like geometry to two equivalent Cr(1) and two equivalent Al(1) atoms. In the second O site, O(2) is bonded in a 4-coordinate geometry to two equivalent Ba(1), two equivalent Cu(1), and two equivalent Al(1) atoms. In the third O site, O(3) is bonded in a 1-coordinate geometry to four equivalent Ba(1) and one Cr(1) atom.
BaCrCuAlO5 crystallizes in the tetragonal P4mm space group. Ba(1) is bonded in a 8-coordinate geometry to four equivalent O(2) and four equivalent O(3) atoms. All Ba(1)-O(2) bond lengths are 3.04 Å. All Ba(1)-O(3) bond lengths are 2.72 Å. Cr(1) is bonded to one O(3) and four equivalent O(1) atoms to form distorted corner-sharing CrO5 trigonal bipyramids. The Cr(1)-O(3) bond length is 1.93 Å. All Cr(1)-O(1) bond lengths are 1.95 Å. Cu(1) is bonded in a distorted square co-planar geometry to four equivalent O(2) atoms. All Cu(1)-O(2) bond lengths are 1.90 Å. Al(1) is bonded in a body-centered cubic geometry to four equivalent O(1) and four equivalent O(2) atoms. All Al(1)-O(1) bond lengths are 2.22 Å. All Al(1)-O(2) bond lengths are 2.28 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted see-saw-like geometry to two equivalent Cr(1) and two equivalent Al(1) atoms. In the second O site, O(2) is bonded in a 4-coordinate geometry to two equivalent Ba(1), two equivalent Cu(1), and two equivalent Al(1) atoms. In the third O site, O(3) is bonded in a 1-coordinate geometry to four equivalent Ba(1) and one Cr(1) atom.