Lu3Si is Uranium Silicide-like structured and crystallizes in the tetragonal I4/mmm space group. There are two inequivalent Lu sites. In the first Lu site, Lu(1) is bonded to four equivalent Lu(1), four equivalent Lu(2), and four equivalent Si(1) atoms to form distorted LuLu8Si4 cuboctahedra that share corners with twelve equivalent Lu(1)Lu8Si4 cuboctahedra, edges with eight equivalent Lu(1)Lu8Si4 cuboctahedra, edges with eight equivalent Si(1)Lu12 cuboctahedra, faces with four equivalent Si(1)Lu12 cuboctahedra, and faces with ten equivalent Lu(1)Lu8Si4 cuboctahedra. In the second Lu site, Lu(2) is bonded in a square co-planar geometry to eight equivalent Lu(1) and four equivalent Si(1) atoms. Si(1) is bonded to four equivalent Lu(2) and eight equivalent Lu(1) atoms to form SiLu12 cuboctahedra that share corners with four equivalent Si(1)Lu12 cuboctahedra, edges with eight equivalent Si(1)Lu12 cuboctahedra, edges with sixteen equivalent Lu(1)Lu8Si4 cuboctahedra, faces with four equivalent Si(1)Lu12 cuboctahedra, and faces with eight equivalent Lu(1)Lu8Si4 cuboctahedra.
Lu3Si is Uranium Silicide-like structured and crystallizes in the tetragonal I4/mmm space group. There are two inequivalent Lu sites. In the first Lu site, Lu(1) is bonded to four equivalent Lu(1), four equivalent Lu(2), and four equivalent Si(1) atoms to form distorted LuLu8Si4 cuboctahedra that share corners with twelve equivalent Lu(1)Lu8Si4 cuboctahedra, edges with eight equivalent Lu(1)Lu8Si4 cuboctahedra, edges with eight equivalent Si(1)Lu12 cuboctahedra, faces with four equivalent Si(1)Lu12 cuboctahedra, and faces with ten equivalent Lu(1)Lu8Si4 cuboctahedra. All Lu(1)-Lu(1) bond lengths are 3.10 Å. All Lu(1)-Lu(2) bond lengths are 3.31 Å. All Lu(1)-Si(1) bond lengths are 3.31 Å. In the second Lu site, Lu(2) is bonded in a square co-planar geometry to eight equivalent Lu(1) and four equivalent Si(1) atoms. All Lu(2)-Si(1) bond lengths are 3.10 Å. Si(1) is bonded to four equivalent Lu(2) and eight equivalent Lu(1) atoms to form SiLu12 cuboctahedra that share corners with four equivalent Si(1)Lu12 cuboctahedra, edges with eight equivalent Si(1)Lu12 cuboctahedra, edges with sixteen equivalent Lu(1)Lu8Si4 cuboctahedra, faces with four equivalent Si(1)Lu12 cuboctahedra, and faces with eight equivalent Lu(1)Lu8Si4 cuboctahedra.