Co6Ta7 is Frank-Kasper $\mu$ Phase-like structured and crystallizes in the trigonal R-3m space group. There are four inequivalent Ta sites. In the first Ta site, Ta(1) is bonded in a distorted hexagonal planar geometry to six equivalent Ta(3) and six equivalent Co(1) atoms. In the second Ta site, Ta(2) is bonded in a 6-coordinate geometry to six equivalent Co(1) atoms. In the third Ta site, Ta(3) is bonded in a 16-coordinate geometry to one Ta(4), three equivalent Ta(1), three equivalent Ta(3), and nine equivalent Co(1) atoms. In the fourth Ta site, Ta(4) is bonded in a 8-coordinate geometry to one Ta(3), one Ta(4), and six equivalent Co(1) atoms. Co(1) is bonded to one Ta(1), two equivalent Ta(2), two equivalent Ta(4), three equivalent Ta(3), and four equivalent Co(1) atoms to form a mixture of distorted corner, edge, and face-sharing CoTa8Co4 cuboctahedra.
Co6Ta7 is Frank-Kasper $\mu$ Phase-like structured and crystallizes in the trigonal R-3m space group. There are four inequivalent Ta sites. In the first Ta site, Ta(1) is bonded in a distorted hexagonal planar geometry to six equivalent Ta(3) and six equivalent Co(1) atoms. All Ta(1)-Ta(3) bond lengths are 2.88 Å. All Ta(1)-Co(1) bond lengths are 2.50 Å. In the second Ta site, Ta(2) is bonded in a 6-coordinate geometry to six equivalent Co(1) atoms. There are three shorter (2.71 Å) and three longer (2.76 Å) Ta(2)-Co(1) bond lengths. In the third Ta site, Ta(3) is bonded in a 16-coordinate geometry to one Ta(4), three equivalent Ta(1), three equivalent Ta(3), and nine equivalent Co(1) atoms. The Ta(3)-Ta(4) bond length is 2.75 Å. All Ta(3)-Ta(3) bond lengths are 2.93 Å. There are three shorter (2.74 Å) and six longer (3.01 Å) Ta(3)-Co(1) bond lengths. In the fourth Ta site, Ta(4) is bonded in a 8-coordinate geometry to one Ta(3), one Ta(4), and six equivalent Co(1) atoms. The Ta(4)-Ta(4) bond length is 2.57 Å. All Ta(4)-Co(1) bond lengths are 2.69 Å. Co(1) is bonded to one Ta(1), two equivalent Ta(2), two equivalent Ta(4), three equivalent Ta(3), and four equivalent Co(1) atoms to form a mixture of distorted corner, edge, and face-sharing CoTa8Co4 cuboctahedra. There are two shorter (2.42 Å) and two longer (2.53 Å) Co(1)-Co(1) bond lengths.