Co3Al is beta Cu3Ti-like structured and crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded to eight Co(1,1) and four equivalent Al(1) atoms to form CoAl4Co8 cuboctahedra that share corners with four equivalent Al(1)Co12 cuboctahedra; corners with fourteen Co(1,1)Al4Co8 cuboctahedra; edges with six equivalent Al(1)Co12 cuboctahedra; edges with twelve Co(1,1)Al4Co8 cuboctahedra; faces with four equivalent Al(1)Co12 cuboctahedra; and faces with sixteen Co(1,1)Al4Co8 cuboctahedra. In the second Co site, Co(1) is bonded to eight Co(1,1) and four equivalent Al(1) atoms to form CoAl4Co8 cuboctahedra that share corners with four equivalent Al(1)Co12 cuboctahedra; corners with fourteen Co(1,1)Al4Co8 cuboctahedra; edges with six equivalent Al(1)Co12 cuboctahedra; edges with twelve Co(1,1)Al4Co8 cuboctahedra; faces with four equivalent Al(1)Co12 cuboctahedra; and faces with sixteen Co(1,1)Al4Co8 cuboctahedra. Al(1) is bonded to twelve Co(1,1) atoms to form AlCo12 cuboctahedra that share corners with six equivalent Al(1)Co12 cuboctahedra; corners with twelve Co(1,1)Al4Co8 cuboctahedra; edges with eighteen Co(1,1)Al4Co8 cuboctahedra; faces with eight equivalent Al(1)Co12 cuboctahedra; and faces with twelve Co(1,1)Al4Co8 cuboctahedra.
Co3Al is beta Cu3Ti-like structured and crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded to eight Co(1,1) and four equivalent Al(1) atoms to form CoAl4Co8 cuboctahedra that share corners with four equivalent Al(1)Co12 cuboctahedra; corners with fourteen Co(1,1)Al4Co8 cuboctahedra; edges with six equivalent Al(1)Co12 cuboctahedra; edges with twelve Co(1,1)Al4Co8 cuboctahedra; faces with four equivalent Al(1)Co12 cuboctahedra; and faces with sixteen Co(1,1)Al4Co8 cuboctahedra. There are a spread of Co(1)-Co(1,1) bond distances ranging from 2.50-2.56 Å. There are two shorter (2.52 Å) and two longer (2.54 Å) Co(1)-Al(1) bond lengths. In the second Co site, Co(1) is bonded to eight Co(1,1) and four equivalent Al(1) atoms to form CoAl4Co8 cuboctahedra that share corners with four equivalent Al(1)Co12 cuboctahedra; corners with fourteen Co(1,1)Al4Co8 cuboctahedra; edges with six equivalent Al(1)Co12 cuboctahedra; edges with twelve Co(1,1)Al4Co8 cuboctahedra; faces with four equivalent Al(1)Co12 cuboctahedra; and faces with sixteen Co(1,1)Al4Co8 cuboctahedra. There are a spread of Co(1)-Co(1) bond distances ranging from 2.50-2.56 Å. There are two shorter (2.52 Å) and two longer (2.54 Å) Co(1)-Al(1) bond lengths. Al(1) is bonded to twelve Co(1,1) atoms to form AlCo12 cuboctahedra that share corners with six equivalent Al(1)Co12 cuboctahedra; corners with twelve Co(1,1)Al4Co8 cuboctahedra; edges with eighteen Co(1,1)Al4Co8 cuboctahedra; faces with eight equivalent Al(1)Co12 cuboctahedra; and faces with twelve Co(1,1)Al4Co8 cuboctahedra.