Materials Data on Cs5As5Se9 by Materials Project

Cs5As5Se9 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are three inequivalent Cs1+ sites. In the first Cs1+ site, Cs1+ is bonded in a 7-coordinate geometry to seven Se2- atoms. There are a spread of Cs–Se bond distances ranging from 3.71–4.21 Å. In the second Cs1+ site, Cs1+ is bonded in a 8-coordinate geometry to eight Se2- atoms. There are a spread of Cs–Se bond distances ranging from 3.66–4.11 Å. In the third Cs1+ site, Cs1+ is bonded in a 6-coordinate geometry to five Se2- atoms. There are a spread of Cs–Se bond distances ranging from 3.78–3.94 Å. There are three inequivalent As+2.60+ sites. In the first As+2.60+ site, As+2.60+ is bonded in a trigonal non-coplanar geometry to three Se2- atoms. There are one shorter (2.35 Å) and two longer (2.48 Å) As–Se bond lengths. In the second As+2.60+ site, As+2.60+ is bonded in a water-like geometry to two Se2- atoms. There are one shorter (2.36 Å) and one longer (2.46 Å) As–Se bond lengths. In the third As+2.60+ site, As+2.60+ is bonded in a trigonal non-coplanar geometry to three Se2- atoms. There are a spread of As–Se bond distances ranging from 2.33–2.50 Å. There are five inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 2-coordinate geometry to three Cs1+ and two As+2.60+ atoms. In the second Se2- site, Se2- is bonded in a 2-coordinate geometry to three Cs1+ and two As+2.60+ atoms. In the third Se2- site, Se2- is bonded in a 1-coordinate geometry to five Cs1+ and one As+2.60+ atom. In the fourth Se2- site, Se2- is bonded in a 1-coordinate geometry to four Cs1+ and one As+2.60+ atom. In the fifth Se2- site, Se2- is bonded in a 1-coordinate geometry to four Cs1+ and one As+2.60+ atom.