Materials Data on SmTiNbBi2O9 by Materials Project
SmTiNbBi2O9 is Esseneite-derived structured and crystallizes in the monoclinic P2_1 space group. The structure is three-dimensional. Sm3+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Sm–O bond distances ranging from 2.34–2.56 Å. Ti4+ is bonded to six O2- atoms to form distorted TiO6 octahedra that share corners with five equivalent NbO6 octahedra. The corner-sharing octahedra tilt angles range from 25–38°. There are a spread of Ti–O bond distances ranging from 1.80–2.25 Å. Nb5+ is bonded to six O2- atoms to form distorted NbO6 octahedra that share corners with five equivalent TiO6 octahedra. The corner-sharing octahedra tilt angles range from 25–38°. There are a spread of Nb–O bond distances ranging from 1.89–2.20 Å. There are two inequivalent Bi3+ sites. In the first 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 2.23–2.71 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 2.23–2.75 Å. There are nine inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to one Ti4+ and two Bi3+ atoms. In the second O2- site, O2- is bonded in a distorted single-bond geometry to one Nb5+ and two Bi3+ atoms. In the third O2- site, O2- is bonded in a 2-coordinate geometry to one Sm3+, one Ti4+, and one Nb5+ atom. In the fourth O2- site, O2- is bonded in a 2-coordinate geometry to one Sm3+, one Ti4+, and one Nb5+ atom. In the fifth O2- site, O2- is bonded in a distorted see-saw-like geometry to two equivalent Sm3+, one Ti4+, and one Nb5+ atom. In the sixth O2- site, O2- is bonded to four Bi3+ atoms to form a mixture of edge and corner-sharing OBi4 tetrahedra. In the seventh O2- site, O2- is bonded to four Bi3+ atoms to form a mixture of edge and corner-sharing OBi4 tetrahedra. In the eighth O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Sm3+, one Ti4+, and one Nb5+ atom. In the ninth O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Sm3+, one Ti4+, and one Nb5+ atom.