Materials Data on Co2AsHO5 by Materials Project

Abstract

Co2(OH)(AsO4) crystallizes in the orthorhombic Pnnm space group. The structure is three-dimensional. there are two inequivalent Co2+ sites. In the first Co2+ site, Co2+ is bonded to six O2- atoms to form CoO6 octahedra that share corners with four equivalent AsO4 tetrahedra, corners with four equivalent CoO5 trigonal bipyramids, and edges with two equivalent CoO6 octahedra. There are a spread of Co–O bond distances ranging from 2.09–2.27 Å. In the second Co2+ site, Co2+ is bonded to five O2- atoms to form CoO5 trigonal bipyramids that share corners with four equivalent CoO6 octahedra, corners with four equivalent AsO4 tetrahedra, and an edgeedge with one CoO5 trigonal bipyramid. The corner-sharing octahedra tilt angles range from 54–66°. There are a spread of Co–O bond distances ranging from 2.02–2.12 Å. As5+ is bonded to four O2- atoms to form AsO4 tetrahedra that share corners with four equivalent CoO6 octahedra and corners with four equivalent CoO5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 56–64°. All As–O bond lengths are 1.73 Å. H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Co2+ and one As5+ atom. In the second O2- site, O2- is bonded in a distorted single-bond geometry to three Co2+ and one H1+ atom. In the third O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Co2+ and one As5+ atom. In the fourth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Co2+ and one As5+ atom.