Materials Data on K4Sb2O3 by Materials Project
K4SbO3Sb crystallizes in the hexagonal P6_3mc space group. The structure is two-dimensional and consists of two antimony molecules and two K4SbO3 sheets oriented in the (0, 0, 1) direction. In each K4SbO3 sheet, there are four inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 3-coordinate geometry to three equivalent O2- atoms. All K–O bond lengths are 2.66 Å. In the second K1+ site, K1+ is bonded in a hexagonal planar geometry to six equivalent O2- atoms. All K–O bond lengths are 3.19 Å. In the third K1+ site, K1+ is bonded in a 6-coordinate geometry to three equivalent O2- atoms. All K–O bond lengths are 2.95 Å. In the fourth K1+ site, K1+ is bonded in a distorted T-shaped geometry to three equivalent O2- atoms. All K–O bond lengths are 2.56 Å. Sb1+ is bonded in a trigonal non-coplanar geometry to three equivalent O2- atoms. All Sb–O bond lengths are 1.93 Å. O2- is bonded to five K1+ and one Sb1+ atom to form a mixture of distorted face and corner-sharing OK5Sb octahedra. The corner-sharing octahedra tilt angles range from 5–60°.