Materials Data on Cd2AsO4F by Materials Project

Abstract

Cd2AsO4F crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. there are two inequivalent Cd2+ sites. In the first Cd2+ site, Cd2+ is bonded to four O2- and two equivalent F1- atoms to form distorted CdO4F2 pentagonal pyramids that share corners with two equivalent CdO4F2 octahedra, corners with four equivalent AsO4 tetrahedra, edges with two equivalent CdO4F2 octahedra, and edges with two equivalent CdO4F2 pentagonal pyramids. The corner-sharing octahedra tilt angles range from 42–68°. There are a spread of Cd–O bond distances ranging from 2.24–2.40 Å. There are one shorter (2.30 Å) and one longer (2.61 Å) Cd–F bond lengths. In the second Cd2+ site, Cd2+ is bonded to four O2- and two equivalent F1- atoms to form distorted CdO4F2 octahedra that share corners with two equivalent CdO4F2 pentagonal pyramids, corners with four equivalent AsO4 tetrahedra, edges with two equivalent CdO4F2 octahedra, and edges with two equivalent CdO4F2 pentagonal pyramids. There are a spread of Cd–O bond distances ranging from 2.25–2.36 Å. There are one shorter (2.33 Å) and one longer (2.49 Å) Cd–F bond lengths. As5+ is bonded to four O2- atoms to form AsO4 tetrahedra that share corners with four equivalent CdO4F2 octahedra and corners with four equivalent CdO4F2 pentagonal pyramids. The corner-sharing octahedra tilt angles range from 48–59°. There is three shorter (1.72 Å) and one longer (1.73 Å) As–O bond length. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Cd2+ and one As5+ atom. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to two Cd2+ and one As5+ atom. In the third O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Cd2+ and one As5+ atom. In the fourth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Cd2+ and one As5+ atom. F1- is bonded in a 4-coordinate geometry to four Cd2+ atoms.