Lu2BaNiO5 crystallizes in the orthorhombic Pnma space group. Ba(1) is bonded in a 11-coordinate geometry to three equivalent O(3), four equivalent O(1), and four equivalent O(2) atoms. There are two inequivalent Lu sites. In the first Lu site, Lu(1) is bonded in a 7-coordinate geometry to one O(3), two equivalent O(1), and four equivalent O(2) atoms. In the second Lu site, Lu(2) is bonded to one O(3), two equivalent O(2), and four equivalent O(1) atoms to form distorted LuO7 pentagonal bipyramids that share corners with five equivalent Ni(1)O5 trigonal bipyramids, edges with two equivalent Lu(2)O7 pentagonal bipyramids, and  an edgeedge with one Ni(1)O5 trigonal bipyramid. Ni(1) is bonded to one O(3), two equivalent O(1), and two equivalent O(2) atoms to form NiO5 trigonal bipyramids that share corners with five equivalent Lu(2)O7 pentagonal bipyramids and  an edgeedge with one Lu(2)O7 pentagonal bipyramid. There are three inequivalent O sites. In the first O site, O(3) is bonded to three equivalent Ba(1), one Lu(1), one Lu(2), and one Ni(1) atom to form a mixture of distorted edge and corner-sharing OBa3Lu2Ni octahedra. The corner-sharing octahedral tilt angles are 4°. In the second O site, O(1) is bonded in a 4-coordinate geometry to two equivalent Ba(1), one Lu(1), two equivalent Lu(2), and one Ni(1) atom. In the third O site, O(2) is bonded in a 6-coordinate geometry to two equivalent Ba(1), one Lu(2), two equivalent Lu(1), and one Ni(1) atom.
Lu2BaNiO5 crystallizes in the orthorhombic Pnma space group. Ba(1) is bonded in a 11-coordinate geometry to three equivalent O(3), four equivalent O(1), and four equivalent O(2) atoms. There is one shorter (2.69 Å) and two longer (2.83 Å) Ba(1)-O(3) bond lengths. There are two shorter (3.01 Å) and two longer (3.23 Å) Ba(1)-O(1) bond lengths. There are two shorter (2.90 Å) and two longer (2.98 Å) Ba(1)-O(2) bond lengths. There are two inequivalent Lu sites. In the first Lu site, Lu(1) is bonded in a 7-coordinate geometry to one O(3), two equivalent O(1), and four equivalent O(2) atoms. The Lu(1)-O(3) bond length is 2.30 Å. Both Lu(1)-O(1) bond lengths are 2.27 Å. There are two shorter (2.29 Å) and two longer (2.35 Å) Lu(1)-O(2) bond lengths. In the second Lu site, Lu(2) is bonded to one O(3), two equivalent O(2), and four equivalent O(1) atoms to form distorted LuO7 pentagonal bipyramids that share corners with five equivalent Ni(1)O5 trigonal bipyramids, edges with two equivalent Lu(2)O7 pentagonal bipyramids, and  an edgeedge with one Ni(1)O5 trigonal bipyramid. The Lu(2)-O(3) bond length is 2.27 Å. Both Lu(2)-O(2) bond lengths are 2.33 Å. There are two shorter (2.26 Å) and two longer (2.33 Å) Lu(2)-O(1) bond lengths. Ni(1) is bonded to one O(3), two equivalent O(1), and two equivalent O(2) atoms to form NiO5 trigonal bipyramids that share corners with five equivalent Lu(2)O7 pentagonal bipyramids and  an edgeedge with one Lu(2)O7 pentagonal bipyramid. The Ni(1)-O(3) bond length is 2.01 Å. Both Ni(1)-O(1) bond lengths are 2.03 Å. Both Ni(1)-O(2) bond lengths are 2.07 Å. There are three inequivalent O sites. In the first O site, O(3) is bonded to three equivalent Ba(1), one Lu(1), one Lu(2), and one Ni(1) atom to form a mixture of distorted edge and corner-sharing OBa3Lu2Ni octahedra. The corner-sharing octahedral tilt angles are 4°. In the second O site, O(1) is bonded in a 4-coordinate geometry to two equivalent Ba(1), one Lu(1), two equivalent Lu(2), and one Ni(1) atom. In the third O site, O(2) is bonded in a 6-coordinate geometry to two equivalent Ba(1), one Lu(2), two equivalent Lu(1), and one Ni(1) atom.