Materials Data on Na2W2O5 by Materials Project

Abstract

Na2W2O5 crystallizes in the orthorhombic Ima2 space group. The structure is three-dimensional. Na1+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Na–O bond distances ranging from 2.33–2.75 Å. There are two inequivalent W4+ sites. In the first W4+ site, W4+ is bonded to six O2- atoms to form WO6 octahedra that share corners with four equivalent WO6 octahedra and corners with two equivalent WO4 tetrahedra. The corner-sharing octahedral tilt angles are 18°. There are a spread of W–O bond distances ranging from 2.06–2.16 Å. In the second W4+ site, W4+ is bonded to four O2- atoms to form WO4 tetrahedra that share corners with two equivalent WO6 octahedra and corners with two equivalent WO4 tetrahedra. The corner-sharing octahedral tilt angles are 45°. There are a spread of W–O bond distances ranging from 1.94–2.04 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 6-coordinate geometry to four equivalent Na1+ and two equivalent W4+ atoms. In the second O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Na1+ and two W4+ atoms. In the third O2- site, O2- is bonded to two equivalent Na1+ and two equivalent W4+ atoms to form distorted corner-sharing ONa2W2 tetrahedra.