Materials Data on LaNb7O12 by Materials Project
LaNb7O12 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. La3+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of La–O bond distances ranging from 2.40–2.93 Å. There are seven inequivalent Nb3+ sites. In the first Nb3+ site, Nb3+ is bonded to five O2- atoms to form a mixture of corner and edge-sharing NbO5 square pyramids. There are a spread of Nb–O bond distances ranging from 2.07–2.23 Å. In the second Nb3+ site, Nb3+ is bonded to five O2- atoms to form NbO5 square pyramids that share corners with two equivalent NbO6 octahedra, corners with seven NbO5 square pyramids, and an edgeedge with one NbO5 square pyramid. The corner-sharing octahedra tilt angles range from 3–46°. There are a spread of Nb–O bond distances ranging from 2.08–2.26 Å. In the third Nb3+ site, Nb3+ is bonded to five O2- atoms to form NbO5 square pyramids that share a cornercorner with one NbO6 octahedra, corners with six NbO5 square pyramids, an edgeedge with one NbO6 octahedra, and an edgeedge with one NbO5 square pyramid. The corner-sharing octahedral tilt angles are 51°. There are a spread of Nb–O bond distances ranging from 2.09–2.18 Å. In the fourth Nb3+ site, Nb3+ is bonded to five O2- atoms to form a mixture of corner and edge-sharing NbO5 square pyramids. There are a spread of Nb–O bond distances ranging from 2.05–2.28 Å. In the fifth Nb3+ site, Nb3+ is bonded to five O2- atoms to form NbO5 square pyramids that share a cornercorner with one NbO6 octahedra, corners with six NbO5 square pyramids, an edgeedge with one NbO6 octahedra, and an edgeedge with one NbO5 square pyramid. The corner-sharing octahedral tilt angles are 46°. There are a spread of Nb–O bond distances ranging from 2.09–2.19 Å. In the sixth Nb3+ site, Nb3+ is bonded to five O2- atoms to form NbO5 square pyramids that share corners with two equivalent NbO6 octahedra and corners with seven NbO5 square pyramids. The corner-sharing octahedra tilt angles range from 9–44°. There are a spread of Nb–O bond distances ranging from 2.10–2.21 Å. In the seventh Nb3+ site, Nb3+ is bonded to six O2- atoms to form NbO6 octahedra that share a cornercorner with one NbO6 octahedra, corners with six NbO5 square pyramids, and edges with two NbO5 square pyramids. The corner-sharing octahedral tilt angles are 0°. There are a spread of Nb–O bond distances ranging from 1.99–2.12 Å. There are thirteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to one La3+ and three Nb3+ atoms. In the second O2- site, O2- is bonded in a 4-coordinate geometry to one La3+ and three Nb3+ atoms. In the third O2- site, O2- is bonded in a 4-coordinate geometry to one La3+ and three Nb3+ atoms. In the fourth O2- site, O2- is bonded in a 4-coordinate geometry to one La3+ and three Nb3+ atoms. In the fifth O2- site, O2- is bonded in a rectangular see-saw-like geometry to one La3+ and three Nb3+ atoms. In the sixth O2- site, O2- is bonded in a 3-coordinate geometry to three Nb3+ atoms. In the seventh O2- site, O2- is bonded in a 3-coordinate geometry to three Nb3+ atoms. In the eighth O2- site, O2- is bonded in a linear geometry to two equivalent Nb3+ atoms. In the ninth O2- site, O2- is bonded in a see-saw-like geometry to four Nb3+ atoms. In the tenth O2- site, O2- is bonded in a square co-planar geometry to four Nb3+ atoms. In the eleventh O2- site, O2- is bonded in a distorted T-shaped geometry to one La3+ and three Nb3+ atoms. In the twelfth O2- site, O2- is bonded in a T-shaped geometry to three Nb3+ atoms. In the thirteenth O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent La3+ and two Nb3+ atoms.