Materials Data on Ta2BiO6F by Materials Project
Ta2BiO6F crystallizes in the orthorhombic Imma 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 TaO6 octahedra that share corners with six TaO6 octahedra and edges with two equivalent BiO6F2 hexagonal bipyramids. The corner-sharing octahedra tilt angles range from 33–43°. There is two shorter (1.97 Å) and four longer (2.02 Å) Ta–O bond length. In the second Ta5+ site, Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with six TaO6 octahedra and edges with four equivalent BiO6F2 hexagonal bipyramids. The corner-sharing octahedra tilt angles range from 43–46°. There is four shorter (1.99 Å) and two longer (2.00 Å) Ta–O bond length. Bi3+ is bonded to six O2- and two equivalent F1- atoms to form distorted BiO6F2 hexagonal bipyramids that share edges with two equivalent BiO6F2 hexagonal bipyramids and edges with six TaO6 octahedra. There are four shorter (2.58 Å) and two longer (2.64 Å) Bi–O bond lengths. Both Bi–F bond lengths are 2.25 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 150 degrees geometry to two equivalent Ta5+ atoms. In the second O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Ta5+ and two equivalent Bi3+ atoms. In the third O2- site, O2- is bonded in a 3-coordinate geometry to two Ta5+ and one Bi3+ atom. F1- is bonded in a bent 120 degrees geometry to two equivalent Bi3+ atoms.