BaLu2CoO5 crystallizes in the orthorhombic Pnma space group. Ba(1) is bonded in a 11-coordinate geometry to three equivalent O(1), four equivalent O(2), and four equivalent O(3) atoms. There are two inequivalent Lu sites. In the first Lu site, Lu(1) is bonded to one O(1), two equivalent O(2), and four equivalent O(3) atoms to form distorted LuO7 pentagonal bipyramids that share corners with five equivalent Co(1)O5 trigonal bipyramids, edges with two equivalent Lu(1)O7 pentagonal bipyramids, and  an edgeedge with one Co(1)O5 trigonal bipyramid. In the second Lu site, Lu(2) is bonded in a 7-coordinate geometry to one O(1), two equivalent O(3), and four equivalent O(2) atoms. Co(1) is bonded to one O(1), two equivalent O(2), and two equivalent O(3) atoms to form distorted CoO5 trigonal bipyramids that share corners with five equivalent Lu(1)O7 pentagonal bipyramids and  an edgeedge with one Lu(1)O7 pentagonal bipyramid. There are three inequivalent O sites. In the first O site, O(1) is bonded to three equivalent Ba(1), one Lu(1), one Lu(2), and one Co(1) atom to form distorted OBa3Lu2Co octahedra that share corners with two equivalent O(1)Ba3Lu2Co octahedra, corners with eight equivalent O(2)Ba2Lu3Co octahedra, edges with two equivalent O(1)Ba3Lu2Co octahedra, and faces with four equivalent O(2)Ba2Lu3Co octahedra. The corner-sharing octahedral tilt angles range from 1-64°. In the second O site, O(2) is bonded to two equivalent Ba(1), one Lu(1), two equivalent Lu(2), and one Co(1) atom to form distorted OBa2Lu3Co octahedra that share corners with four equivalent O(2)Ba2Lu3Co octahedra, corners with four equivalent O(1)Ba3Lu2Co octahedra, edges with two equivalent O(2)Ba2Lu3Co octahedra, faces with two equivalent O(2)Ba2Lu3Co octahedra, and faces with two equivalent O(1)Ba3Lu2Co octahedra. The corner-sharing octahedral tilt angles range from 25-78°. In the third O site, O(3) is bonded in a 4-coordinate geometry to two equivalent Ba(1), one Lu(2), two equivalent Lu(1), and one Co(1) atom.
BaLu2CoO5 crystallizes in the orthorhombic Pnma space group. Ba(1) is bonded in a 11-coordinate geometry to three equivalent O(1), four equivalent O(2), and four equivalent O(3) atoms. There is one shorter (2.74 Å) and two longer (2.84 Å) Ba(1)-O(1) bond lengths. There are two shorter (2.88 Å) and two longer (2.96 Å) Ba(1)-O(2) bond lengths. There are two shorter (3.06 Å) and two longer (3.28 Å) Ba(1)-O(3) bond lengths. There are two inequivalent Lu sites. In the first Lu site, Lu(1) is bonded to one O(1), two equivalent O(2), and four equivalent O(3) atoms to form distorted LuO7 pentagonal bipyramids that share corners with five equivalent Co(1)O5 trigonal bipyramids, edges with two equivalent Lu(1)O7 pentagonal bipyramids, and  an edgeedge with one Co(1)O5 trigonal bipyramid. The Lu(1)-O(1) bond length is 2.27 Å. Both Lu(1)-O(2) bond lengths are 2.32 Å. There are two shorter (2.27 Å) and two longer (2.31 Å) Lu(1)-O(3) bond lengths. In the second Lu site, Lu(2) is bonded in a 7-coordinate geometry to one O(1), two equivalent O(3), and four equivalent O(2) atoms. The Lu(2)-O(1) bond length is 2.30 Å. Both Lu(2)-O(3) bond lengths are 2.26 Å. There are two shorter (2.30 Å) and two longer (2.36 Å) Lu(2)-O(2) bond lengths. Co(1) is bonded to one O(1), two equivalent O(2), and two equivalent O(3) atoms to form distorted CoO5 trigonal bipyramids that share corners with five equivalent Lu(1)O7 pentagonal bipyramids and  an edgeedge with one Lu(1)O7 pentagonal bipyramid. The Co(1)-O(1) bond length is 2.00 Å. Both Co(1)-O(2) bond lengths are 2.10 Å. Both Co(1)-O(3) bond lengths are 2.03 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded to three equivalent Ba(1), one Lu(1), one Lu(2), and one Co(1) atom to form distorted OBa3Lu2Co octahedra that share corners with two equivalent O(1)Ba3Lu2Co octahedra, corners with eight equivalent O(2)Ba2Lu3Co octahedra, edges with two equivalent O(1)Ba3Lu2Co octahedra, and faces with four equivalent O(2)Ba2Lu3Co octahedra. The corner-sharing octahedral tilt angles range from 1-64°. In the second O site, O(2) is bonded to two equivalent Ba(1), one Lu(1), two equivalent Lu(2), and one Co(1) atom to form distorted OBa2Lu3Co octahedra that share corners with four equivalent O(2)Ba2Lu3Co octahedra, corners with four equivalent O(1)Ba3Lu2Co octahedra, edges with two equivalent O(2)Ba2Lu3Co octahedra, faces with two equivalent O(2)Ba2Lu3Co octahedra, and faces with two equivalent O(1)Ba3Lu2Co octahedra. The corner-sharing octahedral tilt angles range from 25-78°. In the third O site, O(3) is bonded in a 4-coordinate geometry to two equivalent Ba(1), one Lu(2), two equivalent Lu(1), and one Co(1) atom.