Materials Data on Cs2Cu5Se4 by Materials Project
Cs2Cu5Se4 crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. there are two inequivalent Cs1+ sites. In the first Cs1+ site, Cs1+ is bonded in a body-centered cubic geometry to eight Se2- atoms. There are a spread of Cs–Se bond distances ranging from 3.58–3.74 Å. In the second Cs1+ site, Cs1+ is bonded in a distorted body-centered cubic geometry to eight Se2- atoms. There are four shorter (3.69 Å) and four longer (3.90 Å) Cs–Se bond lengths. There are three inequivalent Cu+1.20+ sites. In the first Cu+1.20+ site, Cu+1.20+ is bonded to four Se2- atoms to form a mixture of corner and edge-sharing CuSe4 tetrahedra. There are a spread of Cu–Se bond distances ranging from 2.45–2.78 Å. In the second Cu+1.20+ site, Cu+1.20+ is bonded in a trigonal planar geometry to three Se2- atoms. There are two shorter (2.38 Å) and one longer (2.41 Å) Cu–Se bond lengths. In the third Cu+1.20+ site, Cu+1.20+ is bonded in a 1-coordinate geometry to one Cu+1.20+ and four Se2- atoms. The Cu–Cu bond length is 2.46 Å. There are a spread of Cu–Se bond distances ranging from 2.38–2.82 Å. There are three inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 9-coordinate geometry to two equivalent Cs1+ and seven Cu+1.20+ atoms. In the second Se2- site, Se2- is bonded in a 2-coordinate geometry to six Cs1+ and four Cu+1.20+ atoms. In the third Se2- site, Se2- is bonded in a 8-coordinate geometry to four Cs1+ and four Cu+1.20+ atoms.