Materials Data on NaW2(Br3O)2 by Materials Project

Abstract

NaW2(OBr3)2 crystallizes in the monoclinic Cm space group. The structure is two-dimensional and consists of two NaW2(OBr3)2 sheets oriented in the (1, 0, 0) direction. Na1+ is bonded in a body-centered cubic geometry to eight Br1- atoms. There are a spread of Na–Br bond distances ranging from 3.20–3.30 Å. There are two inequivalent W+4.50+ sites. In the first W+4.50+ site, W+4.50+ is bonded to two equivalent O2- and four Br1- atoms to form a mixture of distorted edge and corner-sharing WBr4O2 octahedra. The corner-sharing octahedral tilt angles are 3°. Both W–O bond lengths are 1.94 Å. There are a spread of W–Br bond distances ranging from 2.54–2.71 Å. In the second W+4.50+ site, W+4.50+ is bonded to two equivalent O2- and four Br1- atoms to form a mixture of distorted edge and corner-sharing WBr4O2 octahedra. The corner-sharing octahedral tilt angles are 3°. Both W–O bond lengths are 1.94 Å. There are a spread of W–Br bond distances ranging from 2.54–2.71 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a linear geometry to two equivalent W+4.50+ atoms. In the second O2- site, O2- is bonded in a linear geometry to two equivalent W+4.50+ atoms. There are six inequivalent Br1- sites. In the first Br1- site, Br1- is bonded in a 3-coordinate geometry to two equivalent Na1+ and one W+4.50+ atom. In the second Br1- site, Br1- is bonded in a distorted L-shaped geometry to two W+4.50+ atoms. In the third Br1- site, Br1- is bonded in a 3-coordinate geometry to two equivalent Na1+ and one W+4.50+ atom. In the fourth Br1- site, Br1- is bonded in a 3-coordinate geometry to two equivalent Na1+ and one W+4.50+ atom. In the fifth Br1- site, Br1- is bonded in a 3-coordinate geometry to two equivalent Na1+ and one W+4.50+ atom. In the sixth Br1- site, Br1- is bonded in a distorted L-shaped geometry to two W+4.50+ atoms.