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All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on CaH2 by Materials Project

CaH2 crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. Ca2+ is bonded in a 3-coordinate geometry to eleven H1- atoms. There are a spread of Ca–H bond distances ranging from 2.20–2.67 Å. There are two inequivalent H1- sites. In the first H1- site, H1- is bonded to five equivalent Ca2+ atoms to form distorted HCa5 trigonal bipyramids that share corners with twelve equivalent HCa6 octahedra, corners with eight equivalent HCa5 trigonal bipyramids, edges with six equivalent HCa5 trigonal bipyramids, and faces with six equivalent HCa6 octahedra. The corner-sharing octahedra tilt angles range from 31–59°. In the second H1- site, H1- is bonded to six equivalent Ca2+ atoms to form HCa6 octahedra that share corners with twelve equivalent HCa6 octahedra, corners with twelve equivalent HCa5 trigonal bipyramids, edges with six equivalent HCa6 octahedra, faces with two equivalent HCa6 octahedra, and faces with six equivalent HCa5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 51°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CaH2 by Materials Project

CaH2 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Ca2+ is bonded in a 3-coordinate geometry to eleven H1- atoms. There are a spread of Ca–H bond distances ranging from 2.21–2.74 Å. There are two inequivalent H1- sites. In the first H1- site, H1- is bonded to six equivalent Ca2+ atoms to form a mixture of corner, edge, and face-sharing HCa6 octahedra. The corner-sharing octahedra tilt angles range from 50–52°. In the second H1- site, H1- is bonded in a 5-coordinate geometry to five equivalent Ca2+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CaH2 by Materials Project

CaH2 crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. Ca2+ is bonded in a 3-coordinate geometry to eleven H1- atoms. There are a spread of Ca–H bond distances ranging from 2.20–2.67 Å. There are two inequivalent H1- sites. In the first H1- site, H1- is bonded to five equivalent Ca2+ atoms to form distorted HCa5 trigonal bipyramids that share corners with twelve equivalent HCa6 octahedra, corners with eight equivalent HCa5 trigonal bipyramids, edges with six equivalent HCa5 trigonal bipyramids, and faces with six equivalent HCa6 octahedra. The corner-sharing octahedra tilt angles range from 31–60°. In the second H1- site, H1- is bonded to six equivalent Ca2+ atoms to form HCa6 octahedra that share corners with twelve equivalent HCa6 octahedra, corners with twelve equivalent HCa5 trigonal bipyramids, edges with six equivalent HCa6 octahedra, faces with two equivalent HCa6 octahedra, and faces with six equivalent HCa5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 50–51°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CaH3 by Materials Project

CaH3 is alpha bismuth trifluoride structured and crystallizes in the cubic Fm-3m space group. The structure is three-dimensional. Ca is bonded in a distorted body-centered cubic geometry to fourteen H atoms. There are eight shorter (2.28 Å) and six longer (2.64 Å) Ca–H bond lengths. There are two inequivalent H sites. In the first H site, H is bonded to four equivalent Ca atoms to form HCa4 tetrahedra that share corners with twelve equivalent HCa6 octahedra, corners with sixteen equivalent HCa4 tetrahedra, edges with six equivalent HCa4 tetrahedra, and faces with four equivalent HCa6 octahedra. The corner-sharing octahedral tilt angles are 55°. In the second H site, H is bonded to six equivalent Ca atoms to form HCa6 octahedra that share corners with six equivalent HCa6 octahedra, corners with twenty-four equivalent HCa4 tetrahedra, edges with twelve equivalent HCa6 octahedra, and faces with eight equivalent HCa4 tetrahedra. The corner-sharing octahedral tilt angles are 0°.

36 MATERIALS SCIENCE↗