Materials Data on NaSb3O8 by Materials Project
NaSb3O8 crystallizes in the orthorhombic Ibam space group. The structure is three-dimensional. Na1+ is bonded in a body-centered cubic geometry to eight O2- atoms. There are four shorter (2.53 Å) and four longer (2.59 Å) Na–O bond lengths. There are two inequivalent Sb5+ sites. In the first Sb5+ site, Sb5+ is bonded to seven O2- atoms to form distorted SbO7 trigonal bipyramids that share corners with two equivalent SbO8 hexagonal bipyramids, corners with two equivalent SbO7 trigonal bipyramids, edges with two equivalent SbO8 hexagonal bipyramids, and edges with two equivalent SbO7 trigonal bipyramids. There are a spread of Sb–O bond distances ranging from 1.98–2.50 Å. In the second Sb5+ site, Sb5+ is bonded to eight O2- atoms to form distorted SbO8 hexagonal bipyramids that share corners with four equivalent SbO7 trigonal bipyramids, edges with two equivalent SbO8 hexagonal bipyramids, and edges with four equivalent SbO7 trigonal bipyramids. There are four shorter (2.06 Å) and four longer (2.20 Å) Sb–O bond lengths. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to one Na1+ and three Sb5+ atoms. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to three Sb5+ atoms. In the third O2- site, O2- is bonded to two equivalent Na1+ and two equivalent Sb5+ atoms to form a mixture of distorted corner and edge-sharing ONa2Sb2 tetrahedra.