Materials Data on Na5(AsO9)2 by Materials Project
Na5(AsO8)2O2 crystallizes in the monoclinic P2/c space group. The structure is three-dimensional and consists of two hydrogen peroxide molecules and one Na5(AsO8)2 framework. In the Na5(AsO8)2 framework, there are three inequivalent Na sites. In the first Na site, Na is bonded in a square co-planar geometry to four O atoms. There are two shorter (2.37 Å) and two longer (2.60 Å) Na–O bond lengths. In the second Na site, Na is bonded in a 6-coordinate geometry to six O atoms. There are a spread of Na–O bond distances ranging from 2.27–2.84 Å. In the third Na site, Na is bonded in a 3-coordinate geometry to five O atoms. There are a spread of Na–O bond distances ranging from 2.23–3.00 Å. As is bonded to four O atoms to form corner-sharing AsO4 tetrahedra. There are a spread of As–O bond distances ranging from 1.69–1.88 Å. There are nine inequivalent O sites. In the first O site, O is bonded in a distorted linear geometry to two equivalent Na and two equivalent O atoms. Both O–O bond lengths are 1.86 Å. In the second O site, O is bonded in a bent 120 degrees geometry to one Na and one O atom. The O–O bond length is 1.26 Å. In the third O site, O is bonded in a distorted T-shaped geometry to two Na and one As atom. In the fourth O site, O is bonded in a single-bond geometry to one As atom. In the fifth O site, O is bonded in a distorted trigonal planar geometry to two equivalent Na and one As atom. In the sixth O site, O is bonded in a water-like geometry to one Na and one O atom. The O–O bond length is 1.23 Å. In the seventh O site, O is bonded in a 2-coordinate geometry to two Na and two O atoms. In the eighth O site, O is bonded in a distorted trigonal pyramidal geometry to two equivalent Na and two equivalent As atoms. In the ninth O site, O is bonded in a 4-coordinate geometry to three Na and one O atom. The O–O bond length is 1.27 Å.