Hf6Co16Si7 crystallizes in the cubic Fm-3m space group. Hf(1) is bonded in a 12-coordinate geometry to four equivalent Co(1), four equivalent Co(2), and four equivalent Si(1) atoms. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded in a 13-coordinate geometry to three equivalent Hf(1), three equivalent Co(1), three equivalent Co(2), one Si(2), and three equivalent Si(1) atoms. In the second Co site, Co(2) is bonded in a 12-coordinate geometry to three equivalent Hf(1), three equivalent Co(1), three equivalent Co(2), and three equivalent Si(1) atoms. There are two inequivalent Si sites. In the first Si site, Si(2) is bonded in a body-centered cubic geometry to eight equivalent Co(1) atoms. In the second Si site, Si(1) is bonded to four equivalent Hf(1), four equivalent Co(1), and four equivalent Co(2) atoms to form a mixture of face and corner-sharing SiHf4Co8 cuboctahedra.
Hf6Co16Si7 crystallizes in the cubic Fm-3m space group. Hf(1) is bonded in a 12-coordinate geometry to four equivalent Co(1), four equivalent Co(2), and four equivalent Si(1) atoms. All Hf(1)-Co(1) bond lengths are 2.73 Å. All Hf(1)-Co(2) bond lengths are 2.78 Å. All Hf(1)-Si(1) bond lengths are 2.86 Å. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded in a 13-coordinate geometry to three equivalent Hf(1), three equivalent Co(1), three equivalent Co(2), one Si(2), and three equivalent Si(1) atoms. All Co(1)-Co(1) bond lengths are 2.70 Å. All Co(1)-Co(2) bond lengths are 2.49 Å. The Co(1)-Si(2) bond length is 2.34 Å. All Co(1)-Si(1) bond lengths are 2.48 Å. In the second Co site, Co(2) is bonded in a 12-coordinate geometry to three equivalent Hf(1), three equivalent Co(1), three equivalent Co(2), and three equivalent Si(1) atoms. All Co(2)-Co(2) bond lengths are 2.47 Å. All Co(2)-Si(1) bond lengths are 2.31 Å. There are two inequivalent Si sites. In the first Si site, Si(2) is bonded in a body-centered cubic geometry to eight equivalent Co(1) atoms. In the second Si site, Si(1) is bonded to four equivalent Hf(1), four equivalent Co(1), and four equivalent Co(2) atoms to form a mixture of face and corner-sharing SiHf4Co8 cuboctahedra.