DOE OSTI2020
Co3Cr is beta Cu3Ti-like structured and crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. Cr is bonded to twelve Co atoms to form CrCo12 cuboctahedra that share corners with six equivalent CrCo12 cuboctahedra, corners with twelve CoCr4Co8 cuboctahedra, edges with eighteen CoCr4Co8 cuboctahedra, faces with eight equivalent CrCo12 cuboctahedra, and faces with twelve CoCr4Co8 cuboctahedra. There are six shorter (2.46 Å) and six longer (2.50 Å) Cr–Co bond lengths. There are three inequivalent Co sites. In the first Co site, Co is bonded to four equivalent Cr and eight Co atoms to form CoCr4Co8 cuboctahedra that share corners with four equivalent CrCo12 cuboctahedra, corners with fourteen CoCr4Co8 cuboctahedra, edges with six equivalent CrCo12 cuboctahedra, edges with twelve CoCr4Co8 cuboctahedra, faces with four equivalent CrCo12 cuboctahedra, and faces with sixteen CoCr4Co8 cuboctahedra. There are a spread of Co–Co bond distances ranging from 2.45–2.51 Å. In the second Co site, Co is bonded to four equivalent Cr and eight equivalent Co atoms to form CoCr4Co8 cuboctahedra that share corners with four equivalent CrCo12 cuboctahedra, corners with fourteen CoCr4Co8 cuboctahedra, edges with six equivalent CrCo12 cuboctahedra, edges with twelve equivalent CoCr4Co8 cuboctahedra, faces with four equivalent CrCo12 cuboctahedra, and faces with sixteen CoCr4Co8 cuboctahedra. In the third Co site, Co is bonded to four equivalent Cr and eight equivalent Co atoms to form CoCr4Co8 cuboctahedra that share corners with four equivalent CrCo12 cuboctahedra, corners with fourteen CoCr4Co8 cuboctahedra, edges with six equivalent CrCo12 cuboctahedra, edges with twelve equivalent CoCr4Co8 cuboctahedra, faces with four equivalent CrCo12 cuboctahedra, and faces with sixteen CoCr4Co8 cuboctahedra.