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All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on KCaF3 by Materials Project

KCaF3 is (Cubic) Perovskite structured and crystallizes in the cubic Pm-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 eight equivalent CaF6 octahedra. All K–F bond lengths are 3.17 Å. Ca2+ is bonded to six equivalent F1- atoms to form CaF6 octahedra that share corners with six equivalent CaF6 octahedra and faces with eight equivalent KF12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. All Ca–F bond lengths are 2.24 Å. F1- is bonded in a distorted linear geometry to four equivalent K1+ and two equivalent Ca2+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on KCaF3 by Materials Project

KCaF3 is Orthorhombic Perovskite structured and crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. K1+ is bonded in a 8-coordinate geometry to eight F1- atoms. There are a spread of K–F bond distances ranging from 2.70–3.10 Å. Ca2+ is bonded to six F1- atoms to form corner-sharing CaF6 octahedra. The corner-sharing octahedral tilt angles are 27°. There are two shorter (2.27 Å) and four longer (2.28 Å) Ca–F bond lengths. There are two inequivalent F1- sites. In the first F1- site, F1- is bonded in a 5-coordinate geometry to three equivalent K1+ and two equivalent Ca2+ atoms. In the second F1- site, F1- is bonded to two equivalent K1+ and two equivalent Ca2+ atoms to form distorted corner-sharing FK2Ca2 tetrahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on KCaF3 by Materials Project

KCaF3 is Orthorhombic Perovskite structured and crystallizes in the monoclinic P2_1/m space group. The structure is three-dimensional. there are two inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 8-coordinate geometry to eight F1- atoms. There are a spread of K–F bond distances ranging from 2.67–3.22 Å. In the second K1+ site, K1+ is bonded in a 9-coordinate geometry to nine F1- atoms. There are a spread of K–F bond distances ranging from 2.74–3.30 Å. There are two inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded to six F1- atoms to form corner-sharing CaF6 octahedra. The corner-sharing octahedra tilt angles range from 24–29°. All Ca–F bond lengths are 2.27 Å. In the second Ca2+ site, Ca2+ is bonded to six F1- atoms to form corner-sharing CaF6 octahedra. The corner-sharing octahedra tilt angles range from 22–29°. There are two shorter (2.26 Å) and four longer (2.27 Å) Ca–F bond lengths. There are four inequivalent F1- sites. In the first F1- site, F1- is bonded in a distorted see-saw-like geometry to two K1+ and two equivalent Ca2+ atoms. In the second F1- site, F1- is bonded in a 5-coordinate geometry to three K1+ and two equivalent Ca2+ atoms. In the third F1- site, F1- is bonded in a 5-coordinate geometry to three K1+ and two Ca2+ atoms. In the fourth F1- site, F1- is bonded in a 5-coordinate geometry to three K1+ and two Ca2+ atoms.

36 MATERIALS SCIENCE↗