Materials Data on K7Na(TeO8)4 by Materials Project

Abstract

K7Na(TeO8)4 crystallizes in the orthorhombic Immm space group. The structure is three-dimensional. 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 (3.11 Å) and four longer (3.16 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 (2.70 Å) and four longer (2.75 Å) K–O bond lengths. In the third K site, K is bonded in a 8-coordinate geometry to eight O atoms. There are a spread of K–O bond distances ranging from 3.04–3.44 Å. In the fourth K site, K is bonded in a 8-coordinate geometry to eight equivalent O atoms. All K–O bond lengths are 2.83 Å. Na is bonded to six O atoms to form NaO6 octahedra that share corners with four equivalent TeO5 trigonal bipyramids. There are four shorter (2.30 Å) and two longer (2.61 Å) Na–O bond lengths. Te is bonded to five O atoms to form distorted TeO5 trigonal bipyramids that share a cornercorner with one NaO6 octahedra and an edgeedge with one TeO5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 49°. There are a spread of Te–O bond distances ranging from 1.85–2.11 Å. There are seven inequivalent O sites. In the first O site, O is bonded in a bent 120 degrees geometry to two equivalent O atoms. Both O–O bond lengths are 1.33 Å. 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, one Na, and one O atom. The O–O bond length is 1.30 Å. In the fourth O site, O is bonded in a distorted rectangular see-saw-like geometry to three K and one O atom. 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 K and one Te atom.