Materials Data on U2Co3Si by Materials Project
U2Co3Si is Frank-Kasper $\mu$ Phase-derived structured and crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. U is bonded in a 9-coordinate geometry to one U, nine equivalent Co, and three equivalent Si atoms. The U–U bond length is 2.69 Å. There are three shorter (2.83 Å) and six longer (2.90 Å) U–Co bond lengths. All U–Si bond lengths are 3.01 Å. Co is bonded to six equivalent U, four equivalent Co, and two equivalent Si atoms to form CoU6Co4Si2 cuboctahedra that share corners with four equivalent SiU6Co6 cuboctahedra, corners with fourteen equivalent CoU6Co4Si2 cuboctahedra, edges with six equivalent CoU6Co4Si2 cuboctahedra, faces with six equivalent SiU6Co6 cuboctahedra, and faces with twelve equivalent CoU6Co4Si2 cuboctahedra. There are two shorter (2.56 Å) and two longer (2.57 Å) Co–Co bond lengths. Both Co–Si bond lengths are 2.39 Å. Si is bonded to six equivalent U and six equivalent Co atoms to form SiU6Co6 cuboctahedra that share corners with twelve equivalent CoU6Co4Si2 cuboctahedra, edges with six equivalent SiU6Co6 cuboctahedra, faces with two equivalent SiU6Co6 cuboctahedra, and faces with eighteen equivalent CoU6Co4Si2 cuboctahedra.