DOI: 10.17188/1276512
title: Materials Data on Cs3As7 by Materials Project

description: Cs3As7 crystallizes in the orthorhombic Pbca space group. The structure is three-dimensional. there are three inequivalent Cs1+ sites. In the first Cs1+ site, Cs1+ is bonded in a 8-coordinate geometry to eight As+0.43- atoms. There are a spread of Cs–As bond distances ranging from 3.69–3.89 Å. In the second Cs1+ site, Cs1+ is bonded in a 7-coordinate geometry to seven As+0.43- atoms. There are a spread of Cs–As bond distances ranging from 3.84–4.29 Å. In the third Cs1+ site, Cs1+ is bonded in a 7-coordinate geometry to eight As+0.43- atoms. There are a spread of Cs–As bond distances ranging from 3.76–4.19 Å. There are seven inequivalent As+0.43- sites. In the first As+0.43- site, As+0.43- is bonded in a 6-coordinate geometry to three Cs1+ and three As+0.43- atoms. There are a spread of As–As bond distances ranging from 2.40–2.58 Å. In the second As+0.43- site, As+0.43- is bonded to five Cs1+ and two As+0.43- atoms to form distorted AsCs5As2 pentagonal bipyramids that share corners with two equivalent AsCs3As3 octahedra, corners with four equivalent AsCs5As2 pentagonal bipyramids, corners with five equivalent AsCs4As2 pentagonal pyramids, a cornercorner with one AsCs3As2 square pyramid, an edgeedge with one AsCs3As3 octahedra, an edgeedge with one AsCs4As2 pentagonal pyramid, and edges with two equivalent AsCs3As2 square pyramids. The corner-sharing octahedra tilt angles range from 71–143°. The As–As bond length is 2.46 Å. In the third As+0.43- site, As+0.43- is bonded to three Cs1+ and two As+0.43- atoms to form distorted AsCs3As2 square pyramids that share corners with three equivalent AsCs3As3 octahedra, a cornercorner with one AsCs5As2 pentagonal bipyramid, corners with four equivalent AsCs4As2 pentagonal pyramids, an edgeedge with one AsCs3As3 octahedra, edges with two equivalent AsCs5As2 pentagonal bipyramids, an edgeedge with one AsCs4As2 pentagonal pyramid, and an edgeedge with one AsCs3As2 square pyramid. The corner-sharing octahedra tilt angles range from 28–60°. There are one shorter (2.39 Å) and one longer (2.44 Å) As–As bond lengths. In the fourth As+0.43- site, As+0.43- is bonded to three Cs1+ and three As+0.43- atoms to form distorted AsCs3As3 octahedra that share corners with two equivalent AsCs5As2 pentagonal bipyramids, corners with three equivalent AsCs4As2 pentagonal pyramids, corners with three equivalent AsCs3As2 square pyramids, an edgeedge with one AsCs3As3 octahedra, an edgeedge with one AsCs5As2 pentagonal bipyramid, an edgeedge with one AsCs4As2 pentagonal pyramid, and an edgeedge with one AsCs3As2 square pyramid. The As–As bond length is 2.45 Å. In the fifth As+0.43- site, As+0.43- is bonded to four Cs1+ and two As+0.43- atoms to form distorted AsCs4As2 pentagonal pyramids that share corners with three equivalent AsCs3As3 octahedra, corners with five equivalent AsCs5As2 pentagonal bipyramids, corners with two equivalent AsCs4As2 pentagonal pyramids, corners with four equivalent AsCs3As2 square pyramids, an edgeedge with one AsCs3As3 octahedra, an edgeedge with one AsCs5As2 pentagonal bipyramid, and an edgeedge with one AsCs3As2 square pyramid. The corner-sharing octahedra tilt angles range from 55–143°. The As–As bond length is 2.38 Å. In the sixth As+0.43- site, As+0.43- is bonded in a 6-coordinate geometry to three Cs1+ and three As+0.43- atoms. The As–As bond length is 2.54 Å. In the seventh As+0.43- site, As+0.43- is bonded in a 5-coordinate geometry to two equivalent Cs1+ and three As+0.43- atoms.