DOE OSTI2020
BiTaO4 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are two inequivalent Ta5+ sites. In the first Ta5+ site, Ta5+ is bonded to six O2- atoms to form corner-sharing TaO6 octahedra. The corner-sharing octahedra tilt angles range from 23–38°. There are a spread of Ta–O bond distances ranging from 1.93–2.08 Å. In the second Ta5+ site, Ta5+ is bonded to six O2- atoms to form corner-sharing TaO6 octahedra. The corner-sharing octahedra tilt angles range from 23–38°. There are a spread of Ta–O bond distances ranging from 1.90–2.18 Å. There are two inequivalent Bi3+ sites. In the first Bi3+ site, Bi3+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Bi–O bond distances ranging from 2.26–2.67 Å. In the second Bi3+ site, Bi3+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Bi–O bond distances ranging from 2.22–2.81 Å. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two Ta5+ and one Bi3+ atom. In the second O2- site, O2- is bonded in a 4-coordinate geometry to one Ta5+ and three Bi3+ atoms. In the third O2- site, O2- is bonded in a 4-coordinate geometry to one Ta5+ and three Bi3+ atoms. In the fourth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two Ta5+ and one Bi3+ atom. In the fifth O2- site, O2- is bonded in a 2-coordinate geometry to two Ta5+ and one Bi3+ atom. In the sixth O2- site, O2- is bonded in a 3-coordinate geometry to one Ta5+ and three Bi3+ atoms. In the seventh O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ta5+ and two Bi3+ atoms. In the eighth O2- site, O2- is bonded in a bent 150 degrees geometry to two Ta5+ atoms.