Co7Hf2 is Frank-Kasper $\mu$ Phase-like structured and crystallizes in the monoclinic C2/m space group. There are two inequivalent Hf sites. In the first Hf site, Hf(1) is bonded in a 14-coordinate geometry to two equivalent Co(4), four equivalent Co(1), and eight equivalent Co(2) atoms. In the second Hf site, Hf(2) is bonded in a 14-coordinate geometry to two equivalent Co(4), four equivalent Co(1), and eight equivalent Co(3) atoms. There are four inequivalent Co sites. In the first Co site, Co(1) is bonded to two equivalent Hf(1), two equivalent Hf(2), two equivalent Co(1), two equivalent Co(2), two equivalent Co(3), and two equivalent Co(4) atoms to form a mixture of corner, edge, and face-sharing CoHf4Co8 cuboctahedra. In the second Co site, Co(2) is bonded in a 12-coordinate geometry to four equivalent Hf(1), one Co(4), two equivalent Co(1), and five equivalent Co(2) atoms. In the third Co site, Co(3) is bonded in a 12-coordinate geometry to four equivalent Hf(2), one Co(4), two equivalent Co(1), and five equivalent Co(3) atoms. In the fourth Co site, Co(4) is bonded to two equivalent Hf(1), two equivalent Hf(2), two equivalent Co(2), two equivalent Co(3), and four equivalent Co(1) atoms to form a mixture of corner, edge, and face-sharing CoHf4Co8 cuboctahedra.
Co7Hf2 is Frank-Kasper $\mu$ Phase-like structured and crystallizes in the monoclinic C2/m space group. There are two inequivalent Hf sites. In the first Hf site, Hf(1) is bonded in a 14-coordinate geometry to two equivalent Co(4), four equivalent Co(1), and eight equivalent Co(2) atoms. There is one shorter (2.82 Å) and one longer (2.84 Å) Hf(1)-Co(4) bond length. There are two shorter (2.86 Å) and two longer (2.87 Å) Hf(1)-Co(1) bond lengths. There are a spread of Hf(1)-Co(2) bond distances ranging from 2.72-2.81 Å. In the second Hf site, Hf(2) is bonded in a 14-coordinate geometry to two equivalent Co(4), four equivalent Co(1), and eight equivalent Co(3) atoms. There is one shorter (2.80 Å) and one longer (2.81 Å) Hf(2)-Co(4) bond length. There are two shorter (2.86 Å) and two longer (2.87 Å) Hf(2)-Co(1) bond lengths. There are a spread of Hf(2)-Co(3) bond distances ranging from 2.73-2.80 Å. There are four inequivalent Co sites. In the first Co site, Co(1) is bonded to two equivalent Hf(1), two equivalent Hf(2), two equivalent Co(1), two equivalent Co(2), two equivalent Co(3), and two equivalent Co(4) atoms to form a mixture of corner, edge, and face-sharing CoHf4Co8 cuboctahedra. Both Co(1)-Co(1) bond lengths are 2.32 Å. There is one shorter (2.47 Å) and one longer (2.48 Å) Co(1)-Co(2) bond length. There is one shorter (2.48 Å) and one longer (2.49 Å) Co(1)-Co(3) bond length. There is one shorter (2.37 Å) and one longer (2.38 Å) Co(1)-Co(4) bond length. In the second Co site, Co(2) is bonded in a 12-coordinate geometry to four equivalent Hf(1), one Co(4), two equivalent Co(1), and five equivalent Co(2) atoms. The Co(2)-Co(4) bond length is 2.51 Å. There are a spread of Co(2)-Co(2) bond distances ranging from 2.35-2.76 Å. In the third Co site, Co(3) is bonded in a 12-coordinate geometry to four equivalent Hf(2), one Co(4), two equivalent Co(1), and five equivalent Co(3) atoms. The Co(3)-Co(4) bond length is 2.50 Å. There are a spread of Co(3)-Co(3) bond distances ranging from 2.38-2.78 Å. In the fourth Co site, Co(4) is bonded to two equivalent Hf(1), two equivalent Hf(2), two equivalent Co(2), two equivalent Co(3), and four equivalent Co(1) atoms to form a mixture of corner, edge, and face-sharing CoHf4Co8 cuboctahedra.