Materials Data on Hf2Bi2O7 by Materials Project
Hf2Bi2O7 crystallizes in the monoclinic C2 space group. The structure is three-dimensional. there are two inequivalent Hf4+ sites. In the first Hf4+ site, Hf4+ is bonded to six O2- atoms to form corner-sharing HfO6 octahedra. The corner-sharing octahedra tilt angles range from 37–52°. There are a spread of Hf–O bond distances ranging from 2.02–2.17 Å. In the second Hf4+ site, Hf4+ is bonded to six O2- atoms to form corner-sharing HfO6 octahedra. The corner-sharing octahedra tilt angles range from 39–51°. There are a spread of Hf–O bond distances ranging from 2.05–2.13 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 2.23–3.05 Å. In the second Bi3+ site, Bi3+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Bi–O bond distances ranging from 2.24–2.86 Å. There are ten inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two equivalent Hf4+ and two equivalent Bi3+ atoms. In the second O2- site, O2- is bonded to four Bi3+ atoms to form corner-sharing OBi4 tetrahedra. In the third O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to two Hf4+ and one Bi3+ atom. In the fourth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Hf4+ and one Bi3+ atom. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to two Hf4+ and two Bi3+ atoms. In the sixth O2- site, O2- is bonded in a 3-coordinate geometry to two Hf4+ and one Bi3+ atom. In the seventh O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Hf4+ and two equivalent Bi3+ atoms. In the eighth O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Hf4+ and two equivalent Bi3+ atoms. In the ninth O2- site, O2- is bonded to four Bi3+ atoms to form corner-sharing OBi4 tetrahedra. In the tenth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two equivalent Hf4+ and two equivalent Bi3+ atoms.