DOI: 10.17188/1200096
title: Materials Data on Ca5As4(HO2)10 by Materials Project

description: Ca5As4(HO2)10 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. there are three inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded to six O2- atoms to form distorted CaO6 octahedra that share corners with two equivalent CaO6 octahedra, corners with five AsO4 tetrahedra, and edges with two CaO6 octahedra. The corner-sharing octahedra tilt angles range from 69–71°. There are a spread of Ca–O bond distances ranging from 2.34–2.51 Å. In the second Ca2+ site, Ca2+ is bonded to six O2- atoms to form CaO6 octahedra that share corners with two equivalent CaO6 octahedra, corners with four AsO4 tetrahedra, and an edgeedge with one CaO6 octahedra. The corner-sharing octahedra tilt angles range from 69–71°. There are a spread of Ca–O bond distances ranging from 2.32–2.51 Å. In the third Ca2+ site, Ca2+ is bonded to six O2- atoms to form CaO6 octahedra that share corners with six AsO4 tetrahedra and edges with two equivalent CaO6 octahedra. There are a spread of Ca–O bond distances ranging from 2.32–2.43 Å. There are two inequivalent As5+ sites. In the first As5+ site, As5+ is bonded to four O2- atoms to form AsO4 tetrahedra that share corners with seven CaO6 octahedra. The corner-sharing octahedra tilt angles range from 42–60°. There is three shorter (1.72 Å) and one longer (1.74 Å) As–O bond length. In the second As5+ site, As5+ is bonded to four O2- atoms to form AsO4 tetrahedra that share corners with five CaO6 octahedra. The corner-sharing octahedra tilt angles range from 41–62°. There are a spread of As–O bond distances ranging from 1.70–1.77 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 0.98 Å. In the second H1+ site, H1+ is bonded in a single-bond geometry to two O2- atoms. There is one shorter (1.00 Å) and one longer (1.76 Å) H–O bond length. In the third H1+ site, H1+ is bonded in a single-bond geometry to two O2- atoms. There is one shorter (1.01 Å) and one longer (1.70 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 (1.67 Å) H–O bond length. There are ten inequivalent O2- sites. In the first O2- site, O2- is bonded in a trigonal planar geometry to two Ca2+ and one As5+ atom. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to two Ca2+ and one As5+ atom. In the third O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+, one As5+, and one H1+ atom. In the fourth O2- site, O2- is bonded in a 2-coordinate geometry to one Ca2+ and two H1+ atoms. In the fifth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Ca2+ and one As5+ atom. In the sixth O2- site, O2- is bonded in a distorted water-like geometry to two Ca2+ and two H1+ atoms. In the seventh O2- site, O2- is bonded in a distorted water-like geometry to one As5+ and one H1+ atom. In the eighth O2- site, O2- is bonded in a 4-coordinate geometry to one Ca2+, one As5+, and two H1+ atoms. In the ninth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Ca2+ and one As5+ atom. In the tenth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Ca2+ and one As5+ atom.