Ho5Si4 crystallizes in the orthorhombic Pnma space group. There are three inequivalent Ho sites. In the first Ho site, Ho(1) is bonded to two equivalent Si(1), two equivalent Si(2), and two equivalent Si(3) atoms to form distorted corner-sharing HoSi6 octahedra. The corner-sharing octahedral tilt angles are 55°. In the second Ho site, Ho(2) is bonded in a 6-coordinate geometry to one Si(2), two equivalent Si(1), and four equivalent Si(3) atoms. In the third Ho site, Ho(3) is bonded in a 6-coordinate geometry to one Si(1), two equivalent Si(2), and three equivalent Si(3) atoms. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to two equivalent Ho(1), two equivalent Ho(3), four equivalent Ho(2), and one Si(2) atom. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to two equivalent Ho(1), two equivalent Ho(2), four equivalent Ho(3), and one Si(1) atom. In the third Si site, Si(3) is bonded in a 9-coordinate geometry to one Ho(1), three equivalent Ho(3), four equivalent Ho(2), and one Si(3) atom.
Ho5Si4 crystallizes in the orthorhombic Pnma space group. There are three inequivalent Ho sites. In the first Ho site, Ho(1) is bonded to two equivalent Si(1), two equivalent Si(2), and two equivalent Si(3) atoms to form distorted corner-sharing HoSi6 octahedra. The corner-sharing octahedral tilt angles are 55°. There is one shorter (2.89 Å) and one longer (2.96 Å) Ho(1)-Si(1) bond length. There is one shorter (2.88 Å) and one longer (3.25 Å) Ho(1)-Si(2) bond length. Both Ho(1)-Si(3) bond lengths are 3.05 Å. In the second Ho site, Ho(2) is bonded in a 6-coordinate geometry to one Si(2), two equivalent Si(1), and four equivalent Si(3) atoms. The Ho(2)-Si(2) bond length is 3.12 Å. There is one shorter (3.03 Å) and one longer (3.11 Å) Ho(2)-Si(1) bond length. There are a spread of Ho(2)-Si(3) bond distances ranging from 3.02-3.67 Å. In the third Ho site, Ho(3) is bonded in a 6-coordinate geometry to one Si(1), two equivalent Si(2), and three equivalent Si(3) atoms. The Ho(3)-Si(1) bond length is 3.01 Å. There is one shorter (2.89 Å) and one longer (2.92 Å) Ho(3)-Si(2) bond length. There are a spread of Ho(3)-Si(3) bond distances ranging from 2.84-2.94 Å. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to two equivalent Ho(1), two equivalent Ho(3), four equivalent Ho(2), and one Si(2) atom. The Si(1)-Si(2) bond length is 2.54 Å. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to two equivalent Ho(1), two equivalent Ho(2), four equivalent Ho(3), and one Si(1) atom. In the third Si site, Si(3) is bonded in a 9-coordinate geometry to one Ho(1), three equivalent Ho(3), four equivalent Ho(2), and one Si(3) atom. The Si(3)-Si(3) bond length is 2.47 Å.