Materials Data on Cs6K3AlSb4 by Materials Project

Cs6K3AlSb4 crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. Cs1+ is bonded in a 3-coordinate geometry to four equivalent Cs1+, one K1+, and five Sb3- atoms. All Cs–Cs bond lengths are 4.17 Å. The Cs–K bond length is 3.85 Å. There are a spread of Cs–Sb bond distances ranging from 4.08–4.29 Å. K1+ is bonded in a 4-coordinate geometry to two equivalent Cs1+ and four Sb3- atoms. There are two shorter (3.64 Å) and two longer (3.73 Å) K–Sb bond lengths. Al3+ is bonded in a trigonal planar geometry to three equivalent Sb3- atoms. All Al–Sb bond lengths are 2.69 Å. There are two inequivalent Sb3- sites. In the first Sb3- site, Sb3- is bonded to six equivalent Cs1+ and six equivalent K1+ atoms to form face-sharing SbCs6K6 cuboctahedra. In the second Sb3- site, Sb3- is bonded in a 1-coordinate geometry to eight equivalent Cs1+, two equivalent K1+, and one Al3+ atom.