Materials Data on SrNb2Bi2O9 by Materials Project
SrBi2Nb2O9 crystallizes in the orthorhombic Cmc2_1 space group. The structure is three-dimensional. Sr2+ is bonded in a 12-coordinate geometry to eight O2- atoms. There are a spread of Sr–O bond distances ranging from 2.53–2.74 Å. Nb5+ is bonded to six O2- atoms to form corner-sharing NbO6 octahedra. The corner-sharing octahedra tilt angles range from 20–25°. There are a spread of Nb–O bond distances ranging from 1.91–2.19 Å. Bi3+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Bi–O bond distances ranging from 2.19–2.71 Å. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a 1-coordinate geometry to one Nb5+ and two equivalent Bi3+ atoms. In the second O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Sr2+ and two equivalent Nb5+ atoms. In the third O2- site, O2- is bonded in a 3-coordinate geometry to one Sr2+ and two equivalent Nb5+ atoms. In the fourth O2- site, O2- is bonded to four equivalent Bi3+ atoms to form a mixture of distorted edge and corner-sharing OBi4 tetrahedra. In the fifth O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Sr2+ and two equivalent Nb5+ atoms.