Materials Data on Bi2W2O9 by Materials Project
Bi2W2O9 crystallizes in the orthorhombic Pna2_1 space group. The structure is three-dimensional. there are two inequivalent W6+ sites. In the first W6+ site, W6+ is bonded to six O2- atoms to form corner-sharing WO6 octahedra. The corner-sharing octahedra tilt angles range from 17–28°. There are a spread of W–O bond distances ranging from 1.85–2.08 Å. In the second W6+ site, W6+ is bonded to six O2- atoms to form corner-sharing WO6 octahedra. The corner-sharing octahedra tilt angles range from 17–26°. There are a spread of W–O bond distances ranging from 1.85–2.07 Å. There are two inequivalent Bi3+ sites. In the first Bi3+ site, Bi3+ is bonded in a 7-coordinate geometry to six O2- atoms. There are a spread of Bi–O bond distances ranging from 2.23–2.57 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 2.22–2.54 Å. There are nine inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two equivalent W6+ atoms. In the second O2- site, O2- is bonded in a 1-coordinate geometry to one W6+ and two equivalent Bi3+ atoms. In the third O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two equivalent W6+ atoms. In the fourth O2- site, O2- is bonded in a bent 150 degrees geometry to two equivalent W6+ atoms. In the fifth O2- site, O2- is bonded to four Bi3+ atoms to form a mixture of corner and edge-sharing OBi4 tetrahedra. In the sixth O2- site, O2- is bonded in a 1-coordinate geometry to one W6+ and two equivalent Bi3+ atoms. In the seventh O2- site, O2- is bonded to four Bi3+ atoms to form a mixture of corner and edge-sharing OBi4 tetrahedra. In the eighth O2- site, O2- is bonded in a linear geometry to two W6+ atoms. In the ninth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two equivalent W6+ atoms.