Materials Data on CaAsH5O6 by Materials Project

Abstract

CaAsH5O6 crystallizes in the monoclinic Cc space group. The structure is three-dimensional. Ca2+ is bonded to six O2- atoms to form distorted CaO6 octahedra that share corners with two equivalent CaO6 octahedra, corners with two equivalent AsO4 tetrahedra, and an edgeedge with one AsO4 tetrahedra. The corner-sharing octahedral tilt angles are 42°. There are a spread of Ca–O bond distances ranging from 2.32–2.71 Å. As5+ is bonded to four O2- atoms to form AsO4 tetrahedra that share corners with two equivalent CaO6 octahedra and an edgeedge with one CaO6 octahedra. The corner-sharing octahedra tilt angles range from 64–76°. There are a spread of As–O bond distances ranging from 1.69–1.83 Å. There are five inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the second H1+ site, H1+ is bonded in a distorted linear geometry to two O2- atoms. There is one shorter (1.02 Å) and one longer (1.60 Å) H–O bond length. In the third H1+ site, H1+ is bonded in a distorted bent 150 degrees geometry to two O2- atoms. There is one shorter (1.04 Å) and one longer (1.53 Å) H–O bond length. In the fourth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the fifth H1+ site, H1+ is bonded in a distorted single-bond geometry to two O2- atoms. There is one shorter (1.02 Å) and one longer (1.63 Å) H–O bond length. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded in a water-like geometry to one As5+ and one H1+ atom. In the second O2- site, O2- is bonded in a 1-coordinate geometry to one Ca2+, one As5+, and one H1+ atom. In the third O2- site, O2- is bonded in a 2-coordinate geometry to one Ca2+ and three H1+ atoms. In the fourth O2- site, O2- is bonded in a distorted water-like geometry to one Ca2+ and two H1+ atoms. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+, one As5+, and one H1+ atom. In the sixth O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Ca2+ and one As5+ atom.