Materials Data on K7Na(TeO8)4 by Materials Project

K7Na(TeO8)4 crystallizes in the orthorhombic Immm space group. The structure is two-dimensional and consists of two K7Na(TeO8)4 sheets oriented in the (0, 1, 0) direction. there are four inequivalent K sites. In the first K site, K is bonded in a 8-coordinate geometry to eight O atoms. There are four shorter (2.69 Å) and four longer (3.10 Å) K–O bond lengths. In the second K site, K is bonded in a 8-coordinate geometry to eight O atoms. There are four shorter (2.67 Å) and four longer (2.75 Å) K–O bond lengths. In the third K site, K is bonded in a 6-coordinate geometry to two equivalent O atoms. Both K–O bond lengths are 2.72 Å. In the fourth K site, K is bonded in a hexagonal bipyramidal geometry to eight equivalent O atoms. All K–O bond lengths are 2.80 Å. Na is bonded in a linear geometry to two equivalent O atoms. Both Na–O bond lengths are 2.28 Å. Te is bonded to six O atoms to form edge-sharing TeO6 octahedra. There are a spread of Te–O bond distances ranging from 1.89–2.06 Å. There are seven inequivalent O sites. In the first O site, O is bonded in a single-bond geometry to one Te atom. In the second O site, O is bonded in a 1-coordinate geometry to two K and one Te atom. In the third O site, O is bonded in a 4-coordinate geometry to three K and one O atom. The O–O bond length is 1.29 Å. In the fourth O site, O is bonded in a 1-coordinate geometry to two K and one O atom. The O–O bond length is 1.27 Å. In the fifth O site, O is bonded in a water-like geometry to two equivalent Te atoms. In the sixth O site, O is bonded in a distorted trigonal planar geometry to one Na and two equivalent Te atoms. In the seventh O site, O is bonded in a single-bond geometry to one Te atom.