Materials Data on K6Na3AlSb4 by Materials Project
K6Na3AlSb4 crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. K1+ is bonded in a 5-coordinate geometry to five Sb3- atoms. There are a spread of K–Sb bond distances ranging from 3.66–3.96 Å. Na1+ is bonded to four Sb3- atoms to form a mixture of distorted edge and corner-sharing NaSb4 tetrahedra. There are two shorter (3.36 Å) and two longer (3.43 Å) Na–Sb bond lengths. Al3+ is bonded in a trigonal planar geometry to three equivalent Sb3- atoms. All Al–Sb bond lengths are 2.64 Å. There are two inequivalent Sb3- sites. In the first Sb3- site, Sb3- is bonded in a 1-coordinate geometry to eight equivalent K1+, two equivalent Na1+, and one Al3+ atom. In the second Sb3- site, Sb3- is bonded to six equivalent K1+ and six equivalent Na1+ atoms to form face-sharing SbK6Na6 cuboctahedra.