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All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on Hf6Co16Ge7 by Materials Project

Hf6Co16Ge7 crystallizes in the cubic Fm-3m space group. The structure is three-dimensional. Hf is bonded in a 12-coordinate geometry to eight Co and four equivalent Ge atoms. There are four shorter (2.78 Å) and four longer (2.83 Å) Hf–Co bond lengths. All Hf–Ge bond lengths are 2.93 Å. There are two inequivalent Co sites. In the first Co site, Co is bonded in a 7-coordinate geometry to three equivalent Hf, six Co, and four Ge atoms. There are three shorter (2.55 Å) and three longer (2.77 Å) Co–Co bond lengths. There are one shorter (2.40 Å) and three longer (2.52 Å) Co–Ge bond lengths. In the second Co site, Co is bonded in a 12-coordinate geometry to three equivalent Hf, six Co, and three equivalent Ge atoms. All Co–Co bond lengths are 2.64 Å. All Co–Ge bond lengths are 2.35 Å. There are two inequivalent Ge sites. In the first Ge site, Ge is bonded in a body-centered cubic geometry to eight equivalent Co atoms. In the second Ge site, Ge is bonded to four equivalent Hf and eight Co atoms to form a mixture of corner and face-sharing GeHf4Co8 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Hf4Co4Ge7 by Materials Project

Hf4Co4Ge7 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. there are two inequivalent Hf sites. In the first Hf site, Hf is bonded in a 7-coordinate geometry to seven Ge atoms. There are a spread of Hf–Ge bond distances ranging from 2.73–2.89 Å. In the second Hf site, Hf is bonded to seven Ge atoms to form distorted HfGe7 pentagonal bipyramids that share corners with eight equivalent CoGe6 cuboctahedra, corners with two equivalent HfGe7 pentagonal bipyramids, an edgeedge with one HfGe7 pentagonal bipyramid, faces with four equivalent CoGe6 cuboctahedra, and faces with two equivalent HfGe7 pentagonal bipyramids. There are a spread of Hf–Ge bond distances ranging from 2.73–2.90 Å. Co is bonded to six Ge atoms to form distorted CoGe6 cuboctahedra that share corners with six equivalent CoGe6 cuboctahedra, corners with four equivalent HfGe7 pentagonal bipyramids, edges with three equivalent CoGe6 cuboctahedra, faces with two equivalent CoGe6 cuboctahedra, and faces with two equivalent HfGe7 pentagonal bipyramids. There are a spread of Co–Ge bond distances ranging from 2.43–2.48 Å. There are four inequivalent Ge sites. In the first Ge site, Ge is bonded in a 9-coordinate geometry to five Hf and four equivalent Co atoms. In the second Ge site, Ge is bonded in a 6-coordinate geometry to one Hf, four equivalent Co, and one Ge atom. The Ge–Ge bond length is 2.48 Å. In the third Ge site, Ge is bonded in a 12-coordinate geometry to four Hf and four equivalent Co atoms. In the fourth Ge site, Ge is bonded in a 10-coordinate geometry to eight Hf and two equivalent Ge atoms. There are one shorter (2.59 Å) and one longer (2.61 Å) Ge–Ge bond lengths.

36 MATERIALS SCIENCE↗