RuSr2HoCu2O8 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 distorted SrO12 cuboctahedra that share corners with eight equivalent Sr(1)O12 cuboctahedra, faces with five equivalent Sr(1)O12 cuboctahedra, faces with four equivalent Ru(1)O6 octahedra, and faces with four equivalent Cu(1)O5 square pyramids. Ho(1) is bonded in a body-centered cubic geometry to eight equivalent O(1) atoms. Ru(1) is bonded to two equivalent O(2) and four equivalent O(3) atoms to form RuO6 octahedra that share corners with four equivalent Ru(1)O6 octahedra, corners with two equivalent Cu(1)O5 square pyramids, and faces with eight equivalent Sr(1)O12 cuboctahedra. The corner-sharing octahedra are not tilted. 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 Ru(1)O6 octahedra, corners with four equivalent Cu(1)O5 square pyramids, and faces with four equivalent Sr(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 2°. 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 Ho(1), and two equivalent Cu(1) atoms. In the second O site, O(2) is bonded to four equivalent Sr(1), one Ru(1), and one Cu(1) atom to form a mixture of edge and corner-sharing OSr4CuRu octahedra. The corner-sharing octahedral tilt angles range from 0-11°. In the third O site, O(3) is bonded in a linear geometry to four equivalent Sr(1) and two equivalent Ru(1) atoms.
RuSr2HoCu2O8 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 distorted SrO12 cuboctahedra that share corners with eight equivalent Sr(1)O12 cuboctahedra, faces with five equivalent Sr(1)O12 cuboctahedra, faces with four equivalent Ru(1)O6 octahedra, and faces with four equivalent Cu(1)O5 square pyramids. There are two shorter (2.90 Å) and two longer (2.93 Å) Sr(1)-O(1) bond lengths. There are a spread of Sr(1)-O(2) bond distances ranging from 2.67-2.78 Å. There are two shorter (2.97 Å) and two longer (3.02 Å) Sr(1)-O(3) bond lengths. Ho(1) is bonded in a body-centered cubic geometry to eight equivalent O(1) atoms. There are four shorter (2.39 Å) and four longer (2.40 Å) Ho(1)-O(1) bond lengths. Ru(1) is bonded to two equivalent O(2) and four equivalent O(3) atoms to form RuO6 octahedra that share corners with four equivalent Ru(1)O6 octahedra, corners with two equivalent Cu(1)O5 square pyramids, and faces with eight equivalent Sr(1)O12 cuboctahedra. The corner-sharing octahedra are not tilted. Both Ru(1)-O(2) bond lengths are 2.05 Å. All Ru(1)-O(3) bond lengths are 1.92 Å. 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 Ru(1)O6 octahedra, corners with four equivalent Cu(1)O5 square pyramids, and faces with four equivalent Sr(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 2°. The Cu(1)-O(2) bond length is 2.21 Å. All Cu(1)-O(1) bond lengths are 1.93 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 Ho(1), and two equivalent Cu(1) atoms. In the second O site, O(2) is bonded to four equivalent Sr(1), one Ru(1), and one Cu(1) atom to form a mixture of edge and corner-sharing OSr4CuRu octahedra. The corner-sharing octahedral tilt angles range from 0-11°. In the third O site, O(3) is bonded in a linear geometry to four equivalent Sr(1) and two equivalent Ru(1) atoms.