Materials Data on Cs3As2Cl9 by Materials Project
Cs3As2Cl9 crystallizes in the trigonal P321 space group. The structure is three-dimensional. there are two inequivalent Cs1+ sites. In the first Cs1+ site, Cs1+ is bonded to twelve Cl1- atoms to form CsCl12 cuboctahedra that share corners with twelve CsCl12 cuboctahedra, faces with six equivalent CsCl12 cuboctahedra, and faces with six equivalent AsCl6 octahedra. There are a spread of Cs–Cl bond distances ranging from 3.66–3.90 Å. In the second Cs1+ site, Cs1+ is bonded to twelve Cl1- atoms to form CsCl12 cuboctahedra that share corners with twelve CsCl12 cuboctahedra, faces with six CsCl12 cuboctahedra, and faces with five equivalent AsCl6 octahedra. There are a spread of Cs–Cl bond distances ranging from 3.65–3.87 Å. As3+ is bonded to six Cl1- atoms to form AsCl6 octahedra that share corners with three equivalent AsCl6 octahedra and faces with eight CsCl12 cuboctahedra. The corner-sharing octahedral tilt angles are 5°. There are three shorter (2.35 Å) and three longer (2.75 Å) As–Cl bond lengths. There are two inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded to four Cs1+ and two equivalent As3+ atoms to form a mixture of distorted corner and face-sharing ClCs4As2 octahedra. The corner-sharing octahedra tilt angles range from 0–60°. In the second Cl1- site, Cl1- is bonded in a distorted single-bond geometry to four Cs1+ and one As3+ atom.