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All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on CaTa2Bi2O9 by Materials Project

CaBi2Ta2O9 crystallizes in the orthorhombic Cmc2_1 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 2.38–2.61 Å. Ta5+ is bonded to six O2- atoms to form corner-sharing TaO6 octahedra. The corner-sharing octahedra tilt angles range from 25–31°. There are a spread of Ta–O bond distances ranging from 1.90–2.11 Å. Bi3+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Bi–O bond distances ranging from 2.20–2.57 Å. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to one Ta5+ and two equivalent Bi3+ atoms. In the second O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+ and two equivalent Ta5+ atoms. In the third O2- site, O2- is bonded to two equivalent Ca2+ and two equivalent Ta5+ atoms to form distorted corner-sharing OCa2Ta2 tetrahedra. In the fourth O2- site, O2- is bonded to four equivalent Bi3+ atoms to form a mixture of distorted corner and edge-sharing OBi4 tetrahedra. In the fifth O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Ca2+ and two equivalent Ta5+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CaTa2Bi2O9 by Materials Project

CaBi2Ta2O9 crystallizes in the monoclinic C2/m space group. The structure is two-dimensional and consists of one BiO2 sheet oriented in the (0, 0, 1) direction and one CaTa2O5 sheet oriented in the (0, 0, 1) direction. In the BiO2 sheet, Bi3+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Bi–O bond distances ranging from 2.30–2.95 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to four equivalent Bi3+ atoms. In the second O2- site, O2- is bonded to four equivalent Bi3+ atoms to form a mixture of corner and edge-sharing OBi4 tetrahedra. In the CaTa2O5 sheet, Ca2+ is bonded to twelve O2- atoms to form CaO12 cuboctahedra that share corners with four equivalent CaO12 cuboctahedra, faces with four equivalent CaO12 cuboctahedra, and faces with eight equivalent TaO5 square pyramids. There are eight shorter (2.56 Å) and four longer (2.68 Å) Ca–O bond lengths. Ta5+ is bonded to five O2- atoms to form distorted TaO5 square pyramids that share corners with five equivalent TaO5 square pyramids and faces with four equivalent CaO12 cuboctahedra. There are four shorter (1.93 Å) and one longer (2.10 Å) Ta–O bond lengths. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted linear geometry to four equivalent Ca2+ and two equivalent Ta5+ atoms. In the second O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Ca2+ and two equivalent Ta5+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CaTa2Bi2O9 by Materials Project

Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ca2TaBiO6 by Materials Project

Ca2TaBiO6 crystallizes in the monoclinic P2_1/m space group. The structure is three-dimensional. there are two inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded in a 4-coordinate geometry to eight O2- atoms. There are a spread of Ca–O bond distances ranging from 2.24–2.88 Å. In the second Ca2+ site, Ca2+ is bonded in a 4-coordinate geometry to eight O2- atoms. There are a spread of Ca–O bond distances ranging from 2.35–2.89 Å. Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with two equivalent TaO6 octahedra and corners with four equivalent BiO6 octahedra. The corner-sharing octahedra tilt angles range from 36–39°. There are a spread of Ta–O bond distances ranging from 1.98–2.14 Å. Bi3+ is bonded to six O2- atoms to form BiO6 octahedra that share corners with two equivalent BiO6 octahedra and corners with four equivalent TaO6 octahedra. The corner-sharing octahedra tilt angles range from 37–50°. There are a spread of Bi–O bond distances ranging from 2.25–2.43 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 5-coordinate geometry to three Ca2+, one Ta5+, and one Bi3+ atom. In the second O2- site, O2- is bonded in a 5-coordinate geometry to three Ca2+, one Ta5+, and one Bi3+ atom. In the third O2- site, O2- is bonded to two Ca2+ and two equivalent Ta5+ atoms to form distorted OCa2Ta2 tetrahedra that share corners with two equivalent OCa2Ta2 tetrahedra and corners with two equivalent OCa2Bi2 trigonal pyramids. In the fourth O2- site, O2- is bonded to two Ca2+ and two equivalent Bi3+ atoms to form distorted OCa2Bi2 trigonal pyramids that share corners with two equivalent OCa2Ta2 tetrahedra and corners with two equivalent OCa2Bi2 trigonal pyramids.

36 MATERIALS SCIENCE↗