Materials Data on TaNi by Materials Project
TaNi is Frank-Kasper $\mu$ Phase-like structured and crystallizes in the trigonal R-3m space group. The structure is three-dimensional. there are seven inequivalent Ta sites. In the first Ta site, Ta is bonded in a 9-coordinate geometry to seven Ta and nine equivalent Ni atoms. There are a spread of Ta–Ta bond distances ranging from 2.82–2.89 Å. There are three shorter (2.77 Å) and six longer (3.01 Å) Ta–Ni bond lengths. In the second Ta site, Ta is bonded in a 6-coordinate geometry to four Ta and twelve Ni atoms. There are one shorter (2.81 Å) and three longer (2.89 Å) Ta–Ta bond lengths. There are a spread of Ta–Ni bond distances ranging from 2.73–2.98 Å. In the third Ta site, Ta is bonded in a 6-coordinate geometry to eight Ta and six equivalent Ni atoms. There are one shorter (2.61 Å) and six longer (3.12 Å) Ta–Ta bond lengths. All Ta–Ni bond lengths are 2.67 Å. In the fourth Ta site, Ta is bonded in a 8-coordinate geometry to eight Ta and six equivalent Ni atoms. All Ta–Ta bond lengths are 3.10 Å. All Ta–Ni bond lengths are 2.68 Å. In the fifth Ta site, Ta is bonded in a 6-coordinate geometry to six Ta and six Ni atoms. There are three shorter (2.77 Å) and three longer (2.78 Å) Ta–Ni bond lengths. In the sixth Ta site, Ta is bonded in a 6-coordinate geometry to six Ta and six Ni atoms. There are three shorter (2.76 Å) and three longer (2.77 Å) Ta–Ni bond lengths. In the seventh Ta site, Ta is bonded in a 6-coordinate geometry to six equivalent Ta and six equivalent Ni atoms. All Ta–Ni bond lengths are 2.53 Å. There are three inequivalent Ni sites. In the first Ni site, Ni is bonded to seven Ta and five Ni atoms to form NiTa7Ni5 cuboctahedra that share corners with fifteen NiTa7Ni5 cuboctahedra, edges with five NiTa8Ni4 cuboctahedra, and faces with thirteen NiTa7Ni5 cuboctahedra. There are a spread of Ni–Ni bond distances ranging from 2.44–2.47 Å. In the second Ni site, Ni is bonded to eight Ta and four equivalent Ni atoms to form distorted NiTa8Ni4 cuboctahedra that share corners with thirteen NiTa7Ni5 cuboctahedra, edges with five NiTa8Ni4 cuboctahedra, and faces with ten equivalent NiTa8Ni4 cuboctahedra. There are two shorter (2.40 Å) and two longer (2.49 Å) Ni–Ni bond lengths. In the third Ni site, Ni is bonded to six equivalent Ta and six equivalent Ni atoms to form NiTa6Ni6 cuboctahedra that share corners with twelve equivalent NiTa7Ni5 cuboctahedra, edges with six equivalent NiTa6Ni6 cuboctahedra, and faces with eighteen equivalent NiTa7Ni5 cuboctahedra.