DOE OSTI2020
Co2Ta is Hexagonal Laves-like structured and crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. there are four inequivalent Ta sites. In the first Ta site, Ta is bonded in a 12-coordinate geometry to four Ta and twelve Co atoms. All Ta–Ta bond lengths are 2.91 Å. There are a spread of Ta–Co bond distances ranging from 2.77–2.79 Å. In the second Ta site, Ta is bonded in a 12-coordinate geometry to four Ta and twelve Co atoms. There are one shorter (2.86 Å) and three longer (2.91 Å) Ta–Ta bond lengths. There are six shorter (2.77 Å) and six longer (2.79 Å) Ta–Co bond lengths. In the third Ta site, Ta is bonded in a 12-coordinate geometry to four Ta and twelve Co atoms. The Ta–Ta bond length is 2.91 Å. There are a spread of Ta–Co bond distances ranging from 2.77–2.79 Å. In the fourth Ta site, Ta is bonded in a 12-coordinate geometry to four Ta and twelve Co atoms. There are six shorter (2.77 Å) and six longer (2.79 Å) Ta–Co bond lengths. There are three inequivalent Co sites. In the first Co site, Co is bonded to six Ta and six Co atoms to form a mixture of edge, corner, and face-sharing CoTa6Co6 cuboctahedra. All Co–Co bond lengths are 2.38 Å. In the second Co site, Co is bonded to six Ta and six Co atoms to form a mixture of edge, corner, and face-sharing CoTa6Co6 cuboctahedra. There are a spread of Co–Co bond distances ranging from 2.35–2.40 Å. In the third Co site, Co is bonded to six Ta and six Co atoms to form a mixture of edge, corner, and face-sharing CoTa6Co6 cuboctahedra.