Materials Data on AsH6NO4 by Materials Project
NH4H2AsO4 crystallizes in the orthorhombic P2_12_12_1 space group. The structure is one-dimensional and consists of two NH4H2AsO4 ribbons oriented in the (0, 1, 0) direction. As5+ is bonded in a tetrahedral geometry to four O2- atoms. There are a spread of As–O bond distances ranging from 1.67–1.80 Å. N3- is bonded in a tetrahedral geometry to four H1+ atoms. There are a spread of N–H bond distances ranging from 1.03–1.06 Å. There are six inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one N3- atom. In the second H1+ site, H1+ is bonded in a single-bond geometry to one N3- and one O2- atom. The H–O bond length is 1.66 Å. In the third H1+ site, H1+ is bonded in a single-bond geometry to one N3- atom. In the fourth H1+ site, H1+ is bonded in a single-bond geometry to one N3- atom. In the fifth H1+ site, H1+ is bonded in a distorted single-bond geometry to two O2- atoms. There is one shorter (1.01 Å) and one longer (1.66 Å) H–O bond length. In the sixth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 120 degrees geometry to one As5+ and one H1+ atom. In the second O2- site, O2- is bonded in a distorted water-like geometry to one As5+ and one H1+ atom. In the third O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one As5+ and one H1+ atom. In the fourth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one As5+ and one H1+ atom.