Materials Data on Na4W4O15 by Materials Project
Na4W4O15 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are two inequivalent Na sites. In the first Na site, Na is bonded in a 7-coordinate geometry to seven O atoms. There are a spread of Na–O bond distances ranging from 2.33–2.82 Å. In the second Na site, Na is bonded to five O atoms to form NaO5 square pyramids that share corners with three equivalent WO6 octahedra and an edgeedge with one NaO5 square pyramid. The corner-sharing octahedra tilt angles range from 47–66°. There are a spread of Na–O bond distances ranging from 2.27–2.69 Å. There are two inequivalent W sites. In the first W site, W is bonded to six O atoms to form distorted WO6 octahedra that share corners with three equivalent NaO5 square pyramids and an edgeedge with one WO6 octahedra. There are a spread of W–O bond distances ranging from 1.81–2.15 Å. In the second W site, W is bonded in a 6-coordinate geometry to six O atoms. There are a spread of W–O bond distances ranging from 1.79–2.26 Å. There are eight inequivalent O sites. In the first O site, O is bonded in a 3-coordinate geometry to three W atoms. In the second O site, O is bonded in a 3-coordinate geometry to one Na and two W atoms. In the third O site, O is bonded in a linear geometry to two equivalent Na atoms. In the fourth O site, O is bonded in a 3-coordinate geometry to two Na and one W atom. In the fifth O site, O is bonded in a 4-coordinate geometry to three Na and one W atom. In the sixth O site, O is bonded in a distorted T-shaped geometry to two Na and one W atom. In the seventh O site, O is bonded to two equivalent Na and two W atoms to form distorted edge-sharing ONa2W2 trigonal pyramids. In the eighth O site, O is bonded in a trigonal planar geometry to one Na and two W atoms.