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All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on Ca2Hf7O16 by Materials Project

Ca2Hf7O16 crystallizes in the trigonal R-3 space group. The structure is three-dimensional. there are four inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded in a body-centered cubic geometry to eight O2- atoms. There are a spread of Ca–O bond distances ranging from 2.46–2.58 Å. In the second Ca2+ site, Ca2+ is bonded in a body-centered cubic geometry to eight O2- atoms. There are a spread of Ca–O bond distances ranging from 2.46–2.58 Å. In the third Ca2+ site, Ca2+ is bonded in a body-centered cubic geometry to eight O2- atoms. There are a spread of Ca–O bond distances ranging from 2.46–2.58 Å. In the fourth Ca2+ site, Ca2+ is bonded in a body-centered cubic geometry to eight O2- atoms. There are a spread of Ca–O bond distances ranging from 2.46–2.58 Å. There are seven inequivalent Hf4+ sites. In the first Hf4+ site, Hf4+ is bonded to seven O2- atoms to form distorted HfO7 pentagonal bipyramids that share a cornercorner with one HfO6 octahedra, corners with two equivalent HfO7 pentagonal bipyramids, and edges with seven HfO7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 43°. There are a spread of Hf–O bond distances ranging from 2.03–2.28 Å. In the second Hf4+ site, Hf4+ is bonded to seven O2- atoms to form distorted HfO7 pentagonal bipyramids that share a cornercorner with one HfO6 octahedra, corners with two equivalent HfO7 pentagonal bipyramids, and edges with seven HfO7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 43°. There are a spread of Hf–O bond distances ranging from 2.03–2.28 Å. In the third Hf4+ site, Hf4+ is bonded to six equivalent O2- atoms to form corner-sharing HfO6 octahedra. All Hf–O bond lengths are 2.10 Å. In the fourth Hf4+ site, Hf4+ is bonded to seven O2- atoms to form distorted HfO7 pentagonal bipyramids that share a cornercorner with one HfO6 octahedra, corners with two equivalent HfO7 pentagonal bipyramids, and edges with seven HfO7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 43°. There are a spread of Hf–O bond distances ranging from 2.03–2.28 Å. In the fifth Hf4+ site, Hf4+ is bonded to six equivalent O2- atoms to form corner-sharing HfO6 octahedra. All Hf–O bond lengths are 2.10 Å. In the sixth Hf4+ site, Hf4+ is bonded to seven O2- atoms to form distorted HfO7 pentagonal bipyramids that share a cornercorner with one HfO6 octahedra, corners with two equivalent HfO7 pentagonal bipyramids, and edges with seven HfO7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 43°. There are a spread of Hf–O bond distances ranging from 2.03–2.28 Å. In the seventh Hf4+ site, Hf4+ is bonded to six equivalent O2- atoms to form corner-sharing HfO6 octahedra. All Hf–O bond lengths are 2.10 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to two Ca2+ and two Hf4+ atoms. In the second O2- site, O2- is bonded to one Ca2+ and three equivalent Hf4+ atoms to form a mixture of distorted edge and corner-sharing OCaHf3 tetrahedra. In the third O2- site, O2- is bonded to one Ca2+ and three equivalent Hf4+ atoms to form a mixture of edge and corner-sharing OCaHf3 tetrahedra. In the fourth O2- site, O2- is bonded to four Hf4+ atoms to form a mixture of distorted edge and corner-sharing OHf4 tetrahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CaHf4O9 by Materials Project

CaHf4O9 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. there are three inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded in a distorted body-centered cubic geometry to eight O2- atoms. There are a spread of Ca–O bond distances ranging from 2.34–2.69 Å. In the second Ca2+ site, Ca2+ is bonded in a body-centered cubic geometry to eight O2- atoms. There are a spread of Ca–O bond distances ranging from 2.29–2.54 Å. In the third Ca2+ site, Ca2+ is bonded in a distorted body-centered cubic geometry to eight O2- atoms. There are a spread of Ca–O bond distances ranging from 2.32–2.62 Å. There are nine inequivalent Hf4+ sites. In the first Hf4+ site, Hf4+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Hf–O bond distances ranging from 2.06–2.18 Å. In the second Hf4+ site, Hf4+ is bonded to seven O2- atoms to form distorted HfO7 pentagonal bipyramids that share corners with two HfO6 octahedra, a cornercorner with one HfO7 pentagonal bipyramid, and edges with five HfO7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 40–46°. There are a spread of Hf–O bond distances ranging from 2.11–2.28 Å. In the third Hf4+ site, Hf4+ is bonded to six O2- atoms to form HfO6 octahedra that share corners with two equivalent HfO6 octahedra, corners with four HfO7 pentagonal bipyramids, and edges with two equivalent HfO7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 49°. There are a spread of Hf–O bond distances ranging from 2.04–2.10 Å. In the fourth Hf4+ site, Hf4+ is bonded to seven O2- atoms to form distorted HfO7 pentagonal bipyramids that share corners with two HfO6 octahedra, a cornercorner with one HfO7 pentagonal bipyramid, and edges with four HfO7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 44°. There are a spread of Hf–O bond distances ranging from 2.11–2.25 Å. In the fifth Hf4+ site, Hf4+ is bonded to six O2- atoms to form HfO6 octahedra that share a cornercorner with one HfO6 octahedra, corners with five HfO7 pentagonal bipyramids, and an edgeedge with one HfO7 pentagonal bipyramid. The corner-sharing octahedral tilt angles are 49°. There are a spread of Hf–O bond distances ranging from 2.01–2.15 Å. In the sixth Hf4+ site, Hf4+ is bonded to seven O2- atoms to form distorted HfO7 pentagonal bipyramids that share a cornercorner with one HfO6 octahedra, corners with two HfO7 pentagonal bipyramids, an edgeedge with one HfO6 octahedra, and edges with three HfO7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 47°. There are a spread of Hf–O bond distances ranging from 2.07–2.34 Å. In the seventh Hf4+ site, Hf4+ is bonded in a distorted body-centered cubic geometry to eight O2- atoms. There are a spread of Hf–O bond distances ranging from 2.07–2.57 Å. In the eighth Hf4+ site, Hf4+ is bonded to seven O2- atoms to form distorted HfO7 pentagonal bipyramids that share a cornercorner with one HfO6 octahedra, corners with two HfO7 pentagonal bipyramids, an edgeedge with one HfO6 octahedra, and edges with four HfO7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 49°. There are a spread of Hf–O bond distances ranging from 2.03–2.23 Å. In the ninth Hf4+ site, Hf4+ is bonded to seven O2- atoms to form distorted HfO7 pentagonal bipyramids that share a cornercorner with one HfO6 octahedra, corners with two HfO7 pentagonal bipyramids, and edges with four HfO7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 53°. There are a spread of Hf–O bond distances ranging from 2.08–2.29 Å. There are eighteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to four Hf4+ atoms. In the second O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Ca2+ and two Hf4+ atoms. In the third O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to three Hf4+ atoms. In the fourth O2- site, O2- is bonded to one Ca2+ and three Hf4+ atoms to form a mixture of distorted edge and corner-sharing OCaHf3 tetrahedra. In the fifth O2- site, O2- is bonded to one Ca2+ and three Hf4+ atoms to form a mixture of distorted edge and corner-sharing OCaHf3 tetrahedra. In the sixth O2- site, O2- is bonded in a 4-coordinate geometry to one Ca2+ and three Hf4+ atoms. In the seventh O2- site, O2- is bonded to two Ca2+ and two Hf4+ atoms to form distorted OCa2Hf2 tetrahedra that share corners with five OHf4 tetrahedra and edges with three OCaHf3 tetrahedra. In the eighth O2- site, O2- is bonded in a 4-coordinate geometry to two Ca2+ and two Hf4+ atoms. In the ninth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to three Hf4+ atoms. In the tenth O2- site, O2- is bonded in a 4-coordinate geometry to one Ca2+ and three Hf4+ atoms. In the eleventh O2- site, O2- is bonded to one Ca2+ and three Hf4+ atoms to form distorted OCaHf3 tetrahedra that share corners with eight OHf4 tetrahedra and edges with four OCaHf3 tetrahedra. In the twelfth O2- site, O2- is bonded to four Hf4+ atoms to form a mixture of distorted edge and corner-sharing OHf4 tetrahedra. In the thirteenth O2- site, O2- is bonded to one Ca2+ and three Hf4+ atoms to form a mixture of distorted edge and corner-sharing OCaHf3 tetrahedra. In the fourteenth O2- site, O2- is bonded to one Ca2+ and three Hf4+ atoms to form distorted OCaHf3 tetrahedra that share corners with eight OHf4 tetrahedra and an edgeedge with one OCa2Hf2 tetrahedra. In the fifteenth O2- site, O2- is bonded in a 4-coordinate geometry to one Ca2+ and three Hf4+ atoms. In the sixteenth O2- site, O2- is bonded to four Hf4+ atoms to form distorted OHf4 tetrahedra that share corners with eight OHf4 tetrahedra and edges with two OCaHf3 tetrahedra. In the seventeenth O2- site, O2- is bonded to one Ca2+ and three Hf4+ atoms to form a mixture of edge and corner-sharing OCaHf3 tetrahedra. In the eighteenth O2- site, O2- is bonded to one Ca2+ and three Hf4+ atoms to form OCaHf3 tetrahedra that share corners with eight OHf4 tetrahedra and edges with three OCaHf3 tetrahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ca2HfO4 by Materials Project

Ca2HfO4 crystallizes in the orthorhombic Pbam space group. The structure is three-dimensional. Ca2+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Ca–O bond distances ranging from 2.36–2.86 Å. Hf4+ is bonded to six O2- atoms to form edge-sharing HfO6 octahedra. There are two shorter (2.07 Å) and four longer (2.14 Å) Hf–O bond lengths. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded to four equivalent Ca2+ and one Hf4+ atom to form a mixture of distorted corner and edge-sharing OCa4Hf trigonal bipyramids. In the second O2- site, O2- is bonded in a 5-coordinate geometry to three equivalent Ca2+ and two equivalent Hf4+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CaHfO3 by Materials Project

CaHfO3 is Orthorhombic Perovskite structured and crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Ca2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Ca–O bond distances ranging from 2.35–2.84 Å. Hf4+ is bonded to six O2- atoms to form corner-sharing HfO6 octahedra. The corner-sharing octahedra tilt angles range from 33–34°. All Hf–O bond lengths are 2.09 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded to two equivalent Ca2+ and two equivalent Hf4+ atoms to form distorted corner-sharing OCa2Hf2 tetrahedra. In the second O2- site, O2- is bonded in a 5-coordinate geometry to three equivalent Ca2+ and two equivalent Hf4+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ca6HfO8 by Materials Project

Ca6HfO8 crystallizes in the cubic Fm-3m space group. The structure is three-dimensional. Ca2+ is bonded to six O2- atoms to form CaO6 octahedra that share corners with six equivalent CaO6 octahedra, edges with two equivalent HfO6 octahedra, and edges with eight equivalent CaO6 octahedra. The corner-sharing octahedra tilt angles range from 0–14°. There are two shorter (2.40 Å) and four longer (2.42 Å) Ca–O bond lengths. Hf4+ is bonded to six equivalent O2- atoms to form HfO6 octahedra that share edges with twelve equivalent CaO6 octahedra. All Hf–O bond lengths are 2.11 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded to four equivalent Ca2+ and one Hf4+ atom to form OCa4Hf square pyramids that share corners with nine equivalent OCa4Hf square pyramids, edges with four equivalent OCa6 octahedra, and edges with four equivalent OCa4Hf square pyramids. In the second O2- site, O2- is bonded to six equivalent Ca2+ atoms to form OCa6 octahedra that share corners with six equivalent OCa6 octahedra and edges with twelve equivalent OCa4Hf square pyramids. The corner-sharing octahedral tilt angles are 0°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CaHfO3 by Materials Project

CaHfO3 is (Cubic) Perovskite structured and crystallizes in the cubic Pm-3m space group. The structure is three-dimensional. Ca2+ is bonded to twelve equivalent O2- atoms to form CaO12 cuboctahedra that share corners with twelve equivalent CaO12 cuboctahedra, faces with six equivalent CaO12 cuboctahedra, and faces with eight equivalent HfO6 octahedra. All Ca–O bond lengths are 2.90 Å. Hf4+ is bonded to six equivalent O2- atoms to form HfO6 octahedra that share corners with six equivalent HfO6 octahedra and faces with eight equivalent CaO12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. All Hf–O bond lengths are 2.05 Å. O2- is bonded in a distorted linear geometry to four equivalent Ca2+ and two equivalent Hf4+ atoms.

36 MATERIALS SCIENCE↗