Materials Data on TaGaBi2O7 by Materials Project
Bi2GaTaO7 crystallizes in the orthorhombic Imma space group. The structure is three-dimensional. Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with two equivalent TaO6 octahedra, corners with four equivalent GaO6 octahedra, and edges with six BiO8 hexagonal bipyramids. The corner-sharing octahedra tilt angles range from 45–46°. There are four shorter (2.00 Å) and two longer (2.02 Å) Ta–O bond lengths. Ga3+ is bonded to six O2- atoms to form GaO6 octahedra that share corners with two equivalent GaO6 octahedra, corners with four equivalent TaO6 octahedra, and edges with six BiO8 hexagonal bipyramids. The corner-sharing octahedra tilt angles range from 46–48°. There are two shorter (2.02 Å) and four longer (2.06 Å) Ga–O bond lengths. There are two inequivalent Bi3+ sites. In the first Bi3+ site, Bi3+ is bonded to eight O2- atoms to form distorted BiO8 hexagonal bipyramids that share edges with six BiO8 hexagonal bipyramids, edges with two equivalent GaO6 octahedra, and edges with four equivalent TaO6 octahedra. There are a spread of Bi–O bond distances ranging from 2.26–2.63 Å. In the second Bi3+ site, Bi3+ is bonded to eight O2- atoms to form distorted BiO8 hexagonal bipyramids that share edges with six BiO8 hexagonal bipyramids, edges with two equivalent TaO6 octahedra, and edges with four equivalent GaO6 octahedra. There are a spread of Bi–O bond distances ranging from 2.30–2.61 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Ta5+ and two equivalent Bi3+ atoms. In the second O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Ga3+ and two equivalent Bi3+ atoms. In the third O2- site, O2- is bonded in a 4-coordinate geometry to one Ta5+, one Ga3+, and two Bi3+ atoms. In the fourth O2- site, O2- is bonded to four Bi3+ atoms to form corner-sharing OBi4 tetrahedra.