Sr2YFeCu2O7 crystallizes in the orthorhombic Pmmm space group. Sr(1) is bonded in a 10-coordinate geometry to two equivalent O(1), two equivalent O(3), two equivalent O(4), and four equivalent O(2) atoms. Y(1) is bonded in a body-centered cubic geometry to four equivalent O(3) and four equivalent O(4) atoms. Fe(1) is bonded in a square co-planar geometry to two equivalent O(1) and two equivalent O(2) atoms. Cu(1) is bonded to one O(2), two equivalent O(3), and two equivalent O(4) atoms to form corner-sharing CuO5 square pyramids. There are four inequivalent O sites. In the first O site, O(1) is bonded to four equivalent Sr(1) and two equivalent Fe(1) atoms to form distorted OSr4Fe2 octahedra that share corners with two equivalent O(1)Sr4Fe2 octahedra, corners with four equivalent O(3)Sr2Y2Cu2 octahedra, corners with eight equivalent O(2)Sr4FeCu octahedra, edges with two equivalent O(3)Sr2Y2Cu2 octahedra, edges with two equivalent O(1)Sr4Fe2 octahedra, and faces with four equivalent O(2)Sr4FeCu octahedra. The corner-sharing octahedral tilt angles range from 0-68°. In the second O site, O(2) is bonded to four equivalent Sr(1), one Fe(1), and one Cu(1) atom to form distorted OSr4FeCu octahedra that share corners with four equivalent O(3)Sr2Y2Cu2 octahedra, corners with four equivalent O(1)Sr4Fe2 octahedra, corners with five equivalent O(2)Sr4FeCu octahedra, edges with four equivalent O(2)Sr4FeCu octahedra, faces with two equivalent O(3)Sr2Y2Cu2 octahedra, and faces with two equivalent O(1)Sr4Fe2 octahedra. The corner-sharing octahedral tilt angles range from 0-68°. In the third O site, O(3) is bonded to two equivalent Sr(1), two equivalent Y(1), and two equivalent Cu(1) atoms to form distorted OSr2Y2Cu2 octahedra that share corners with two equivalent O(1)Sr4Fe2 octahedra, corners with four equivalent O(3)Sr2Y2Cu2 octahedra, corners with four equivalent O(2)Sr4FeCu octahedra,  an edgeedge with one O(1)Sr4Fe2 octahedra, edges with three equivalent O(3)Sr2Y2Cu2 octahedra, and faces with two equivalent O(2)Sr4FeCu octahedra. The corner-sharing octahedral tilt angles range from 0-57°. In the fourth O site, O(4) is bonded in a 6-coordinate geometry to two equivalent Sr(1), two equivalent Y(1), and two equivalent Cu(1) atoms.
Sr2YFeCu2O7 crystallizes in the orthorhombic Pmmm space group. Sr(1) is bonded in a 10-coordinate geometry to two equivalent O(1), two equivalent O(3), two equivalent O(4), and four equivalent O(2) atoms. Both Sr(1)-O(1) bond lengths are 2.88 Å. Both Sr(1)-O(3) bond lengths are 2.85 Å. Both Sr(1)-O(4) bond lengths are 2.93 Å. All Sr(1)-O(2) bond lengths are 2.72 Å. Y(1) is bonded in a body-centered cubic geometry to four equivalent O(3) and four equivalent O(4) atoms. All Y(1)-O(3) bond lengths are 2.39 Å. All Y(1)-O(4) bond lengths are 2.42 Å. Fe(1) is bonded in a square co-planar geometry to two equivalent O(1) and two equivalent O(2) atoms. Both Fe(1)-O(1) bond lengths are 1.94 Å. Both Fe(1)-O(2) bond lengths are 1.88 Å. Cu(1) is bonded to one O(2), two equivalent O(3), and two equivalent O(4) atoms to form corner-sharing CuO5 square pyramids. The Cu(1)-O(2) bond length is 2.20 Å. Both Cu(1)-O(3) bond lengths are 1.96 Å. Both Cu(1)-O(4) bond lengths are 1.90 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded to four equivalent Sr(1) and two equivalent Fe(1) atoms to form distorted OSr4Fe2 octahedra that share corners with two equivalent O(1)Sr4Fe2 octahedra, corners with four equivalent O(3)Sr2Y2Cu2 octahedra, corners with eight equivalent O(2)Sr4FeCu octahedra, edges with two equivalent O(3)Sr2Y2Cu2 octahedra, edges with two equivalent O(1)Sr4Fe2 octahedra, and faces with four equivalent O(2)Sr4FeCu octahedra. The corner-sharing octahedral tilt angles range from 0-68°. In the second O site, O(2) is bonded to four equivalent Sr(1), one Fe(1), and one Cu(1) atom to form distorted OSr4FeCu octahedra that share corners with four equivalent O(3)Sr2Y2Cu2 octahedra, corners with four equivalent O(1)Sr4Fe2 octahedra, corners with five equivalent O(2)Sr4FeCu octahedra, edges with four equivalent O(2)Sr4FeCu octahedra, faces with two equivalent O(3)Sr2Y2Cu2 octahedra, and faces with two equivalent O(1)Sr4Fe2 octahedra. The corner-sharing octahedral tilt angles range from 0-68°. In the third O site, O(3) is bonded to two equivalent Sr(1), two equivalent Y(1), and two equivalent Cu(1) atoms to form distorted OSr2Y2Cu2 octahedra that share corners with two equivalent O(1)Sr4Fe2 octahedra, corners with four equivalent O(3)Sr2Y2Cu2 octahedra, corners with four equivalent O(2)Sr4FeCu octahedra,  an edgeedge with one O(1)Sr4Fe2 octahedra, edges with three equivalent O(3)Sr2Y2Cu2 octahedra, and faces with two equivalent O(2)Sr4FeCu octahedra. The corner-sharing octahedral tilt angles range from 0-57°. In the fourth O site, O(4) is bonded in a 6-coordinate geometry to two equivalent Sr(1), two equivalent Y(1), and two equivalent Cu(1) atoms.