DOI: 10.17188/1203452
title: Materials Data on NaNb10O18 by Materials Project

description: NaNb10O18 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Na1+ is bonded to twelve O2- atoms to form NaO12 cuboctahedra that share corners with two equivalent NbO6 octahedra, corners with four NbO5 square pyramids, edges with six NbO5 square pyramids, faces with four NbO6 octahedra, and faces with two equivalent NbO5 square pyramids. The corner-sharing octahedral tilt angles are 43°. There are a spread of Na–O bond distances ranging from 2.77–2.99 Å. There are five inequivalent Nb+3.50+ sites. In the first Nb+3.50+ site, Nb+3.50+ is bonded to five O2- atoms to form NbO5 square pyramids that share corners with four NbO6 octahedra, corners with six NbO5 square pyramids, an edgeedge with one NaO12 cuboctahedra, and a faceface with one NaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 3–45°. There are a spread of Nb–O bond distances ranging from 2.09–2.20 Å. In the second Nb+3.50+ site, Nb+3.50+ is bonded to five O2- atoms to form NbO5 square pyramids that share a cornercorner with one NaO12 cuboctahedra, a cornercorner with one NbO6 octahedra, corners with five NbO5 square pyramids, an edgeedge with one NaO12 cuboctahedra, and edges with two NbO6 octahedra. The corner-sharing octahedral tilt angles are 48°. There are a spread of Nb–O bond distances ranging from 2.05–2.20 Å. In the third Nb+3.50+ site, Nb+3.50+ is bonded to five O2- atoms to form NbO5 square pyramids that share a cornercorner with one NaO12 cuboctahedra, corners with three NbO6 octahedra, corners with five NbO5 square pyramids, an edgeedge with one NaO12 cuboctahedra, and an edgeedge with one NbO6 octahedra. The corner-sharing octahedra tilt angles range from 4–55°. There are a spread of Nb–O bond distances ranging from 2.07–2.28 Å. In the fourth Nb+3.50+ site, Nb+3.50+ is bonded to six O2- atoms to form NbO6 octahedra that share a cornercorner with one NaO12 cuboctahedra, corners with two equivalent NbO6 octahedra, corners with four NbO5 square pyramids, edges with two NbO6 octahedra, an edgeedge with one NbO5 square pyramid, and a faceface with one NaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 9–42°. There are a spread of Nb–O bond distances ranging from 2.00–2.16 Å. In the fifth Nb+3.50+ site, Nb+3.50+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with two equivalent NbO6 octahedra, corners with four NbO5 square pyramids, an edgeedge with one NbO6 octahedra, edges with two NbO5 square pyramids, and a faceface with one NaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 9–42°. There are a spread of Nb–O bond distances ranging from 1.97–2.10 Å. There are nine inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to three Nb+3.50+ atoms. In the second O2- site, O2- is bonded in a 4-coordinate geometry to one Na1+ and three Nb+3.50+ atoms. In the third O2- site, O2- is bonded in a distorted T-shaped geometry to one Na1+ and three Nb+3.50+ atoms. In the fourth O2- site, O2- is bonded in a 3-coordinate geometry to three Nb+3.50+ atoms. In the fifth O2- site, O2- is bonded in a distorted T-shaped geometry to one Na1+ and three Nb+3.50+ atoms. In the sixth O2- site, O2- is bonded in a T-shaped geometry to three Nb+3.50+ atoms. In the seventh O2- site, O2- is bonded in a distorted T-shaped geometry to one Na1+ and three Nb+3.50+ atoms. In the eighth O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+ and three Nb+3.50+ atoms. In the ninth O2- site, O2- is bonded in a 4-coordinate geometry to one Na1+ and three Nb+3.50+ atoms.