Materials Data on Na(AsO2)2 by Materials Project
Na(AsO2)2 crystallizes in the monoclinic C2/c space group. The structure is two-dimensional and consists of two Na(AsO2)2 sheets oriented in the (1, 0, 0) direction. there are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Na–O bond distances ranging from 2.36–2.82 Å. In the second Na1+ site, Na1+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Na–O bond distances ranging from 2.28–2.65 Å. There are four inequivalent As+3.50+ sites. In the first As+3.50+ site, As+3.50+ is bonded in a distorted trigonal non-coplanar geometry to three O2- atoms. There are a spread of As–O bond distances ranging from 1.69–1.93 Å. In the second As+3.50+ site, As+3.50+ is bonded in a trigonal non-coplanar geometry to three O2- atoms. There are a spread of As–O bond distances ranging from 1.69–1.91 Å. In the third As+3.50+ site, As+3.50+ is bonded in a trigonal non-coplanar geometry to three O2- atoms. There are a spread of As–O bond distances ranging from 1.68–1.80 Å. In the fourth As+3.50+ site, As+3.50+ is bonded in a trigonal non-coplanar geometry to three O2- atoms. There are a spread of As–O bond distances ranging from 1.69–1.89 Å. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Na1+ and one As+3.50+ atom. In the second O2- site, O2- is bonded in a bent 120 degrees geometry to two As+3.50+ atoms. In the third O2- site, O2- is bonded in a trigonal planar geometry to two Na1+ and one As+3.50+ atom. In the fourth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Na1+ and two As+3.50+ atoms. In the fifth O2- site, O2- is bonded in a bent 120 degrees geometry to two As+3.50+ atoms. In the sixth O2- site, O2- is bonded in a distorted T-shaped geometry to two Na1+ and one As+3.50+ atom. In the seventh O2- site, O2- is bonded in a 2-coordinate geometry to two Na1+ and two As+3.50+ atoms. In the eighth O2- site, O2- is bonded in a distorted T-shaped geometry to two equivalent Na1+ and one As+3.50+ atom.