Materials Data on Co7Mo6 by Materials Project
Co7Mo6 is Frank-Kasper $\mu$ Phase structured and crystallizes in the trigonal R-3m space group. The structure is three-dimensional. there are three inequivalent Mo sites. In the first Mo site, Mo is bonded in a 6-coordinate geometry to nine Mo and six equivalent Co atoms. There are a spread of Mo–Mo bond distances ranging from 2.74–3.03 Å. There are three shorter (2.65 Å) and three longer (2.69 Å) Mo–Co bond lengths. In the second Mo site, Mo is bonded in a 6-coordinate geometry to four Mo and twelve Co atoms. There are one shorter (2.63 Å) and three longer (2.83 Å) Mo–Mo bond lengths. There are a spread of Mo–Co bond distances ranging from 2.70–2.87 Å. In the third Mo site, Mo is bonded in a 8-coordinate geometry to eight Mo and six equivalent Co atoms. The Mo–Mo bond length is 2.54 Å. All Mo–Co bond lengths are 2.59 Å. There are two inequivalent Co sites. In the first Co site, Co is bonded to seven Mo and five Co atoms to form a mixture of corner, edge, and face-sharing CoCo5Mo7 cuboctahedra. There are a spread of Co–Co bond distances ranging from 2.37–2.40 Å. In the second Co site, Co is bonded to six equivalent Mo and six equivalent Co atoms to form CoCo6Mo6 cuboctahedra that share corners with twelve equivalent CoCo5Mo7 cuboctahedra, edges with six equivalent CoCo6Mo6 cuboctahedra, and faces with eighteen equivalent CoCo5Mo7 cuboctahedra.