Materials Data on Na2Nb2W2O13 by Materials Project
Na2Nb2W2O13 crystallizes in the orthorhombic Imm2 space group. The structure is three-dimensional. Na is bonded to seven O atoms to form NaO7 hexagonal pyramids that share a cornercorner with one NaO7 hexagonal pyramid, an edgeedge with one NaO7 hexagonal pyramid, edges with two equivalent WO6 octahedra, and edges with four equivalent NbO6 octahedra. There are a spread of Na–O bond distances ranging from 2.56–2.71 Å. Nb is bonded to six O atoms to form NbO6 octahedra that share corners with two equivalent NbO6 octahedra, corners with four equivalent WO6 octahedra, and edges with four equivalent NaO7 hexagonal pyramids. The corner-sharing octahedra tilt angles range from 37–45°. There are a spread of Nb–O bond distances ranging from 1.98–2.03 Å. W is bonded to six O atoms to form WO6 octahedra that share corners with two equivalent WO6 octahedra, corners with four equivalent NbO6 octahedra, and edges with two equivalent NaO7 hexagonal pyramids. The corner-sharing octahedra tilt angles range from 34–39°. There are a spread of W–O bond distances ranging from 1.92–1.98 Å. There are seven inequivalent O sites. In the first O site, O is bonded in a 3-coordinate geometry to one Na, one Nb, and one W atom. In the second O site, O is bonded in a bent 150 degrees geometry to two equivalent W atoms. In the third O site, O is bonded in a 4-coordinate geometry to two equivalent Na and two equivalent Nb atoms. In the fourth O site, O is bonded in a 3-coordinate geometry to one Na, one Nb, and one W atom. In the fifth O site, O is bonded in a bent 150 degrees geometry to two equivalent W atoms. In the sixth O site, O is bonded in a 4-coordinate geometry to two equivalent Na and two equivalent Nb atoms. In the seventh O site, O is bonded in an L-shaped geometry to two equivalent Na atoms.