DOI: 10.17188/1286398
title: Materials Data on Na3As3(HO5)2 by Materials Project

description: Na3As3(HO5)2 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. there are four inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded to five O2- atoms to form distorted NaO5 square pyramids that share corners with four AsO4 tetrahedra, an edgeedge with one NaO6 octahedra, and an edgeedge with one NaO5 square pyramid. There are a spread of Na–O bond distances ranging from 2.37–2.65 Å. In the second Na1+ site, Na1+ is bonded in a 3-coordinate geometry to three O2- atoms. There are a spread of Na–O bond distances ranging from 2.25–2.31 Å. In the third Na1+ site, Na1+ is bonded to six O2- atoms to form distorted NaO6 octahedra that share corners with four equivalent AsO4 tetrahedra and edges with two equivalent NaO5 square pyramids. There are a spread of Na–O bond distances ranging from 2.44–2.87 Å. In the fourth Na1+ site, Na1+ is bonded in a distorted rectangular see-saw-like geometry to four O2- atoms. There are two shorter (2.38 Å) and two longer (2.41 Å) Na–O bond lengths. There are three inequivalent As5+ sites. In the first As5+ site, As5+ is bonded to four O2- atoms to form AsO4 tetrahedra that share corners with three equivalent NaO5 square pyramids and a cornercorner with one AsO4 tetrahedra. There are a spread of As–O bond distances ranging from 1.69–1.78 Å. In the second As5+ site, As5+ is bonded in a distorted T-shaped geometry to three O2- atoms. There are a spread of As–O bond distances ranging from 1.72–1.92 Å. In the third As5+ site, As5+ is bonded to four O2- atoms to form AsO4 tetrahedra that share corners with two equivalent NaO6 octahedra, a cornercorner with one NaO5 square pyramid, and a cornercorner with one AsO4 tetrahedra. The corner-sharing octahedra tilt angles range from 50–69°. There are a spread of As–O bond distances ranging from 1.67–1.81 Å. There are two inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a 2-coordinate geometry to two O2- atoms. There is one shorter (1.03 Å) and one longer (1.58 Å) H–O bond length. In the second H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 1.00 Å. There are ten inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one H1+ and one O2- atom. The O–O bond length is 1.48 Å. In the second O2- site, O2- is bonded to three Na1+ and one As5+ atom to form distorted edge-sharing ONa3As tetrahedra. In the third O2- site, O2- is bonded in a rectangular see-saw-like geometry to three Na1+ and one As5+ atom. In the fourth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to one Na1+, one As5+, and one H1+ atom. In the fifth O2- site, O2- is bonded in a 1-coordinate geometry to one As5+ and one O2- atom. In the sixth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two As5+ atoms. In the seventh O2- site, O2- is bonded in a 1-coordinate geometry to one Na1+, one As5+, and one H1+ atom. In the eighth O2- site, O2- is bonded in a 3-coordinate geometry to two Na1+ and one As5+ atom. In the ninth O2- site, O2- is bonded in a 4-coordinate geometry to three Na1+ and one As5+ atom. In the tenth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two As5+ atoms.