DOI: 10.17188/1307507
title: Materials Data on Zn2As2O7 by Materials Project

description: Zn2As2O7 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. there are three inequivalent Zn2+ sites. In the first Zn2+ site, Zn2+ is bonded to five O2- atoms to form ZnO5 trigonal bipyramids that share corners with five AsO4 tetrahedra, an edgeedge with one ZnO6 octahedra, and an edgeedge with one ZnO5 trigonal bipyramid. There are a spread of Zn–O bond distances ranging from 2.00–2.11 Å. In the second Zn2+ site, Zn2+ is bonded to six O2- atoms to form distorted ZnO6 octahedra that share corners with six AsO4 tetrahedra and edges with three ZnO5 trigonal bipyramids. There are a spread of Zn–O bond distances ranging from 2.06–2.23 Å. In the third Zn2+ site, Zn2+ is bonded to five O2- atoms to form ZnO5 trigonal bipyramids that share corners with five AsO4 tetrahedra and edges with two equivalent ZnO6 octahedra. There are a spread of Zn–O bond distances ranging from 1.97–2.11 Å. There are three inequivalent As5+ sites. In the first As5+ site, As5+ is bonded to four O2- atoms to form AsO4 tetrahedra that share a cornercorner with one ZnO6 octahedra, a cornercorner with one AsO4 tetrahedra, and corners with four ZnO5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 51°. There are a spread of As–O bond distances ranging from 1.67–1.79 Å. In the second As5+ site, As5+ is bonded to four O2- atoms to form AsO4 tetrahedra that share corners with three equivalent ZnO6 octahedra, a cornercorner with one AsO4 tetrahedra, and corners with three equivalent ZnO5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 42–54°. There is three shorter (1.71 Å) and one longer (1.77 Å) As–O bond length. In the third As5+ site, As5+ is bonded to four O2- atoms to form AsO4 tetrahedra that share corners with two equivalent ZnO6 octahedra, a cornercorner with one AsO4 tetrahedra, and corners with three ZnO5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 49–51°. There are a spread of As–O bond distances ranging from 1.68–1.79 Å. There are eleven inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to two Zn2+ and one As5+ atom. In the second O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two equivalent As5+ atoms. In the third O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Zn2+ and one As5+ atom. In the fourth O2- site, O2- is bonded in a bent 150 degrees geometry to two As5+ atoms. In the fifth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Zn2+ and one As5+ atom. In the sixth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Zn2+ and one As5+ atom. In the seventh O2- site, O2- is bonded in a bent 150 degrees geometry to one Zn2+ and one As5+ atom. In the eighth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Zn2+ and one As5+ atom. In the ninth O2- site, O2- is bonded in a bent 150 degrees geometry to one Zn2+ and one As5+ atom. In the tenth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to two Zn2+ and one As5+ atom. In the eleventh O2- site, O2- is bonded in a distorted trigonal planar geometry to two Zn2+ and one As5+ atom.