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All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on K2HfF6 by Materials Project

K2HfF6 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. K1+ is bonded in a 10-coordinate geometry to ten F1- atoms. There are a spread of K–F bond distances ranging from 2.73–3.18 Å. Hf4+ is bonded in a 8-coordinate geometry to eight F1- atoms. There are a spread of Hf–F bond distances ranging from 2.05–2.23 Å. There are three inequivalent F1- sites. In the first F1- site, F1- is bonded in a 2-coordinate geometry to two equivalent K1+ and two equivalent Hf4+ atoms. In the second F1- site, F1- is bonded in a 1-coordinate geometry to four equivalent K1+ and one Hf4+ atom. In the third F1- site, F1- is bonded in a 1-coordinate geometry to four equivalent K1+ and one Hf4+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on K2HfF6 by Materials Project

K2HfF6 crystallizes in the cubic Fm-3m space group. The structure is three-dimensional. K1+ is bonded to twelve equivalent F1- atoms to form KF12 cuboctahedra that share corners with twelve equivalent KF12 cuboctahedra, faces with six equivalent KF12 cuboctahedra, and faces with four equivalent HfF6 octahedra. All K–F bond lengths are 3.10 Å. Hf4+ is bonded to six equivalent F1- atoms to form HfF6 octahedra that share faces with eight equivalent KF12 cuboctahedra. All Hf–F bond lengths are 2.00 Å. F1- is bonded in a single-bond geometry to four equivalent K1+ and one Hf4+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on K2HfF6 by Materials Project

K2HfF6 crystallizes in the hexagonal P-62m space group. The structure is three-dimensional. K1+ is bonded in a 9-coordinate geometry to nine F1- atoms. There are three shorter (2.64 Å) and six longer (2.83 Å) K–F bond lengths. Hf4+ is bonded in a 9-coordinate geometry to nine F1- atoms. There are three shorter (2.07 Å) and six longer (2.25 Å) Hf–F bond lengths. There are two inequivalent F1- sites. In the first F1- site, F1- is bonded to two equivalent K1+ and two equivalent Hf4+ atoms to form a mixture of distorted edge and corner-sharing FK2Hf2 tetrahedra. In the second F1- site, F1- is bonded in a distorted single-bond geometry to four equivalent K1+ and one Hf4+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on K2HfF6 by Materials Project

K2HfF6 crystallizes in the tetragonal P4/mnc space group. The structure is three-dimensional. K1+ is bonded in a 8-coordinate geometry to eight F1- atoms. There are four shorter (2.70 Å) and four longer (3.29 Å) K–F bond lengths. Hf4+ is bonded in an octahedral geometry to six F1- atoms. There are two shorter (2.00 Å) and four longer (2.01 Å) Hf–F bond lengths. There are two inequivalent F1- sites. In the first F1- site, F1- is bonded in a single-bond geometry to four equivalent K1+ and one Hf4+ atom. In the second F1- site, F1- is bonded in a distorted trigonal non-coplanar geometry to two equivalent K1+ and one Hf4+ atom.

36 MATERIALS SCIENCE↗