SEARCH · Engineering Papers
Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
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
BiTa7O19 crystallizes in the hexagonal P-6c2 space group. The structure is three-dimensional. there are two inequivalent Ta5+ sites. In the first Ta5+ site, Ta5+ is bonded in an octahedral geometry to six equivalent O2- atoms. All Ta–O bond lengths are 2.01 Å. In the second Ta5+ site, Ta5+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Ta–O bond distances ranging from 1.92–2.47 Å. Bi3+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are six shorter (2.45 Å) and two longer (2.70 Å) Bi–O bond lengths. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to three equivalent Ta5+ and one Bi3+ atom. In the second O2- site, O2- is bonded in a bent 150 degrees geometry to two equivalent Ta5+ atoms. In the third O2- site, O2- is bonded in a 3-coordinate geometry to two Ta5+ and one Bi3+ atom. In the fourth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to three equivalent Ta5+ atoms. In the fifth O2- site, O2- is bonded in a trigonal planar geometry to three equivalent Ta5+ atoms.