Materials Data on NaI3O8 by Materials Project
NaO8I3 crystallizes in the tetragonal P-4 space group. The structure is three-dimensional. there are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are four shorter (2.45 Å) and four longer (2.75 Å) Na–O bond lengths. In the second Na1+ site, Na1+ is bonded in a tetrahedral geometry to four equivalent O2- atoms. All Na–O bond lengths are 2.38 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 1-coordinate geometry to one Na1+ and two equivalent I5+ atoms. There are one shorter (1.81 Å) and one longer (2.68 Å) O–I bond lengths. In the second O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Na1+ and one I5+ atom. The O–I bond length is 1.82 Å. In the third O2- site, O2- is bonded in a 1-coordinate geometry to three I5+ atoms. There are a spread of O–I bond distances ranging from 1.85–2.81 Å. In the fourth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Na1+ and two I5+ atoms. There are one shorter (1.97 Å) and one longer (2.07 Å) O–I bond lengths. There are two inequivalent I5+ sites. In the first I5+ site, I5+ is bonded in a distorted see-saw-like geometry to four O2- atoms. In the second I5+ site, I5+ is bonded in a 6-coordinate geometry to six O2- atoms.