Materials Data on KNa5TeO6 by Materials Project
KNa5TeO6 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. K1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of K–O bond distances ranging from 2.75–2.79 Å. There are four inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a distorted rectangular see-saw-like geometry to four O2- atoms. There are a spread of Na–O bond distances ranging from 2.30–2.33 Å. In the second Na1+ site, Na1+ is bonded in a distorted rectangular see-saw-like geometry to four O2- atoms. There are two shorter (2.32 Å) and two longer (2.34 Å) Na–O bond lengths. In the third Na1+ site, Na1+ is bonded in a distorted rectangular see-saw-like geometry to four O2- atoms. There are two shorter (2.36 Å) and two longer (2.40 Å) Na–O bond lengths. In the fourth Na1+ site, Na1+ is bonded in a distorted square co-planar geometry to four O2- atoms. There are two shorter (2.33 Å) and two longer (2.34 Å) Na–O bond lengths. Te6+ is bonded in an octahedral geometry to six O2- atoms. There are a spread of Te–O bond distances ranging from 1.98–2.02 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded to one K1+, four Na1+, and one Te6+ atom to form distorted OKNa4Te octahedra that share corners with five equivalent OKNa4Te octahedra, edges with three equivalent OKNa3Te square pyramids, and a faceface with one OKNa3Te square pyramid. The corner-sharing octahedra tilt angles range from 0–50°. In the second O2- site, O2- is bonded in a 5-coordinate geometry to one K1+, three Na1+, and one Te6+ atom. In the third O2- site, O2- is bonded to one K1+, three Na1+, and one Te6+ atom to form distorted OKNa3Te square pyramids that share corners with four equivalent OKNa3Te square pyramids, edges with three equivalent OKNa4Te octahedra, and a faceface with one OKNa4Te octahedra.