Sr2GdCr(CuO4)2 crystallizes in the orthorhombic Amm2 space group. Sr(1) is bonded to four equivalent O(1), four equivalent O(2), and four equivalent O(3) atoms to form SrO12 cuboctahedra that share corners with eight equivalent Sr(1)O12 cuboctahedra, faces with five equivalent Sr(1)O12 cuboctahedra, faces with four equivalent Cr(1)O6 octahedra, and faces with four equivalent Cu(1)O5 square pyramids. Gd(1) is bonded in a body-centered cubic geometry to eight equivalent O(1) atoms. Cr(1) is bonded to two equivalent O(2) and four equivalent O(3) atoms to form CrO6 octahedra that share corners with four equivalent Cr(1)O6 octahedra, corners with two equivalent Cu(1)O5 square pyramids, and faces with eight equivalent Sr(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 1°. Cu(1) is bonded to one O(2) and four equivalent O(1) atoms to form CuO5 square pyramids that share  a cornercorner with one Cr(1)O6 octahedra, corners with four equivalent Cu(1)O5 square pyramids, and faces with four equivalent Sr(1)O12 cuboctahedra. The corner-sharing octahedra are not tilted. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to two equivalent Sr(1), two equivalent Gd(1), and two equivalent Cu(1) atoms. In the second O site, O(2) is bonded to four equivalent Sr(1), one Cr(1), and one Cu(1) atom to form a mixture of distorted corner and edge-sharing OSr4CrCu octahedra. The corner-sharing octahedral tilt angles range from 0-1°. In the third O site, O(3) is bonded in a distorted linear geometry to four equivalent Sr(1) and two equivalent Cr(1) atoms.
Sr2GdCr(CuO4)2 crystallizes in the orthorhombic Amm2 space group. Sr(1) is bonded to four equivalent O(1), four equivalent O(2), and four equivalent O(3) atoms to form SrO12 cuboctahedra that share corners with eight equivalent Sr(1)O12 cuboctahedra, faces with five equivalent Sr(1)O12 cuboctahedra, faces with four equivalent Cr(1)O6 octahedra, and faces with four equivalent Cu(1)O5 square pyramids. There are two shorter (3.05 Å) and two longer (3.09 Å) Sr(1)-O(1) bond lengths. There are a spread of Sr(1)-O(2) bond distances ranging from 2.71-2.74 Å. There are two shorter (2.70 Å) and two longer (2.72 Å) Sr(1)-O(3) bond lengths. Gd(1) is bonded in a body-centered cubic geometry to eight equivalent O(1) atoms. All Gd(1)-O(1) bond lengths are 2.42 Å. Cr(1) is bonded to two equivalent O(2) and four equivalent O(3) atoms to form CrO6 octahedra that share corners with four equivalent Cr(1)O6 octahedra, corners with two equivalent Cu(1)O5 square pyramids, and faces with eight equivalent Sr(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 1°. Both Cr(1)-O(2) bond lengths are 1.92 Å. There are two shorter (1.92 Å) and two longer (1.93 Å) Cr(1)-O(3) bond lengths. Cu(1) is bonded to one O(2) and four equivalent O(1) atoms to form CuO5 square pyramids that share  a cornercorner with one Cr(1)O6 octahedra, corners with four equivalent Cu(1)O5 square pyramids, and faces with four equivalent Sr(1)O12 cuboctahedra. The corner-sharing octahedra are not tilted. The Cu(1)-O(2) bond length is 2.04 Å. All Cu(1)-O(1) bond lengths are 1.96 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to two equivalent Sr(1), two equivalent Gd(1), and two equivalent Cu(1) atoms. In the second O site, O(2) is bonded to four equivalent Sr(1), one Cr(1), and one Cu(1) atom to form a mixture of distorted corner and edge-sharing OSr4CrCu octahedra. The corner-sharing octahedral tilt angles range from 0-1°. In the third O site, O(3) is bonded in a distorted linear geometry to four equivalent Sr(1) and two equivalent Cr(1) atoms.