Y2BaCuO5 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 Y sites. In the first Y site, Y(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 Y site, Y(2) is bonded to one O(3), two equivalent O(2), and four equivalent O(1) atoms to form distorted YO7 pentagonal bipyramids that share corners with five equivalent Cu(1)O5 square pyramids, edges with two equivalent Y(2)O7 pentagonal bipyramids, and  an edgeedge with one Cu(1)O5 square pyramid. Cu(1) is bonded to one O(3), two equivalent O(1), and two equivalent O(2) atoms to form distorted CuO5 square pyramids that share corners with five equivalent Y(2)O7 pentagonal bipyramids and  an edgeedge with one Y(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 Y(1), one Y(2), and one Cu(1) atom to form a mixture of corner and edge-sharing OBa3Y2Cu octahedra. The corner-sharing octahedral tilt angles are 5°. In the second O site, O(1) is bonded in a 4-coordinate geometry to two equivalent Ba(1), one Y(1), two equivalent Y(2), and one Cu(1) atom. In the third O site, O(2) is bonded in a 6-coordinate geometry to two equivalent Ba(1), one Y(2), two equivalent Y(1), and one Cu(1) atom.
Y2BaCuO5 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 (2.64 Å) and two longer (2.86 Å) Ba(1)-O(3) bond lengths. There are two shorter (3.11 Å) and two longer (3.31 Å) Ba(1)-O(1) bond lengths. There are two shorter (2.99 Å) and two longer (3.04 Å) Ba(1)-O(2) bond lengths. There are two inequivalent Y sites. In the first Y site, Y(1) is bonded in a 7-coordinate geometry to one O(3), two equivalent O(1), and four equivalent O(2) atoms. The Y(1)-O(3) bond length is 2.31 Å. Both Y(1)-O(1) bond lengths are 2.33 Å. There are two shorter (2.35 Å) and two longer (2.39 Å) Y(1)-O(2) bond lengths. In the second Y site, Y(2) is bonded to one O(3), two equivalent O(2), and four equivalent O(1) atoms to form distorted YO7 pentagonal bipyramids that share corners with five equivalent Cu(1)O5 square pyramids, edges with two equivalent Y(2)O7 pentagonal bipyramids, and  an edgeedge with one Cu(1)O5 square pyramid. The Y(2)-O(3) bond length is 2.29 Å. Both Y(2)-O(2) bond lengths are 2.40 Å. There are two shorter (2.32 Å) and two longer (2.38 Å) Y(2)-O(1) bond lengths. Cu(1) is bonded to one O(3), two equivalent O(1), and two equivalent O(2) atoms to form distorted CuO5 square pyramids that share corners with five equivalent Y(2)O7 pentagonal bipyramids and  an edgeedge with one Y(2)O7 pentagonal bipyramid. The Cu(1)-O(3) bond length is 2.30 Å. Both Cu(1)-O(1) bond lengths are 2.00 Å. Both Cu(1)-O(2) bond lengths are 2.03 Å. There are three inequivalent O sites. In the first O site, O(3) is bonded to three equivalent Ba(1), one Y(1), one Y(2), and one Cu(1) atom to form a mixture of corner and edge-sharing OBa3Y2Cu octahedra. The corner-sharing octahedral tilt angles are 5°. In the second O site, O(1) is bonded in a 4-coordinate geometry to two equivalent Ba(1), one Y(1), two equivalent Y(2), and one Cu(1) atom. In the third O site, O(2) is bonded in a 6-coordinate geometry to two equivalent Ba(1), one Y(2), two equivalent Y(1), and one Cu(1) atom.