Sr3Ru2O7 crystallizes in the orthorhombic Ccce space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 9-coordinate geometry to four equivalent O(1) and five equivalent O(2) atoms. In the second Sr site, Sr(2) is bonded to four equivalent O(3) and eight equivalent O(1) atoms to form distorted SrO12 cuboctahedra that share corners with four equivalent Sr(2)O12 cuboctahedra, faces with four equivalent Sr(2)O12 cuboctahedra, and faces with eight equivalent Ru(1)O6 octahedra. Ru(1) is bonded to one O(2), one O(3), and four equivalent O(1) atoms to form RuO6 octahedra that share corners with five equivalent Ru(1)O6 octahedra and faces with four equivalent Sr(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-17°. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 6-coordinate geometry to two equivalent Sr(1), two equivalent Sr(2), and two equivalent Ru(1) atoms. In the second O site, O(2) is bonded to five equivalent Sr(1) and one Ru(1) atom to form OSr5Ru octahedra that share  a cornercorner with one O(3)Sr4Ru2 octahedra, corners with four equivalent O(2)Sr5Ru octahedra, and edges with eight equivalent O(2)Sr5Ru octahedra. The corner-sharing octahedral tilt angles range from 0-7°. In the third O site, O(3) is bonded to four equivalent Sr(2) and two equivalent Ru(1) atoms to form OSr4Ru2 octahedra that share corners with two equivalent O(2)Sr5Ru octahedra, corners with four equivalent O(3)Sr4Ru2 octahedra, and edges with four equivalent O(3)Sr4Ru2 octahedra. The corner-sharing octahedra are not tilted.
Sr3Ru2O7 crystallizes in the orthorhombic Ccce space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 9-coordinate geometry to four equivalent O(1) and five equivalent O(2) atoms. There are two shorter (2.50 Å) and two longer (2.91 Å) Sr(1)-O(1) bond lengths. There is one shorter (2.47 Å) and four longer (2.77 Å) Sr(1)-O(2) bond lengths. In the second Sr site, Sr(2) is bonded to four equivalent O(3) and eight equivalent O(1) atoms to form distorted SrO12 cuboctahedra that share corners with four equivalent Sr(2)O12 cuboctahedra, faces with four equivalent Sr(2)O12 cuboctahedra, and faces with eight equivalent Ru(1)O6 octahedra. All Sr(2)-O(3) bond lengths are 2.76 Å. There are four shorter (2.60 Å) and four longer (3.00 Å) Sr(2)-O(1) bond lengths. Ru(1) is bonded to one O(2), one O(3), and four equivalent O(1) atoms to form RuO6 octahedra that share corners with five equivalent Ru(1)O6 octahedra and faces with four equivalent Sr(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-17°. The Ru(1)-O(2) bond length is 2.02 Å. The Ru(1)-O(3) bond length is 2.01 Å. All Ru(1)-O(1) bond lengths are 1.97 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 6-coordinate geometry to two equivalent Sr(1), two equivalent Sr(2), and two equivalent Ru(1) atoms. In the second O site, O(2) is bonded to five equivalent Sr(1) and one Ru(1) atom to form OSr5Ru octahedra that share  a cornercorner with one O(3)Sr4Ru2 octahedra, corners with four equivalent O(2)Sr5Ru octahedra, and edges with eight equivalent O(2)Sr5Ru octahedra. The corner-sharing octahedral tilt angles range from 0-7°. In the third O site, O(3) is bonded to four equivalent Sr(2) and two equivalent Ru(1) atoms to form OSr4Ru2 octahedra that share corners with two equivalent O(2)Sr5Ru octahedra, corners with four equivalent O(3)Sr4Ru2 octahedra, and edges with four equivalent O(3)Sr4Ru2 octahedra. The corner-sharing octahedra are not tilted.