Materials Data on K2Te4O9 by Materials Project
K2Te4O9 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are two inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of K–O bond distances ranging from 2.65–3.03 Å. In the second K1+ site, K1+ is bonded in a 7-coordinate geometry to eight O2- atoms. There are a spread of K–O bond distances ranging from 2.75–3.35 Å. There are four inequivalent Te4+ sites. In the first Te4+ site, Te4+ is bonded in a distorted see-saw-like geometry to four O2- atoms. There are a spread of Te–O bond distances ranging from 1.89–2.42 Å. In the second Te4+ site, Te4+ is bonded in a distorted rectangular see-saw-like geometry to four O2- atoms. There are a spread of Te–O bond distances ranging from 1.85–2.37 Å. In the third Te4+ site, Te4+ is bonded in a distorted rectangular see-saw-like geometry to four O2- atoms. There are a spread of Te–O bond distances ranging from 1.89–2.40 Å. In the fourth Te4+ site, Te4+ is bonded to five O2- atoms to form distorted edge-sharing TeO5 square pyramids. There are a spread of Te–O bond distances ranging from 1.88–2.49 Å. There are nine inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to three K1+ and one Te4+ atom. In the second O2- site, O2- is bonded in a bent 120 degrees geometry to two Te4+ atoms. In the third O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent K1+ and two Te4+ atoms. In the fourth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two K1+ and two Te4+ atoms. In the fifth O2- site, O2- is bonded in a 2-coordinate geometry to one K1+ and two Te4+ atoms. In the sixth O2- site, O2- is bonded in a 1-coordinate geometry to one K1+ and two equivalent Te4+ atoms. In the seventh O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent K1+ and two Te4+ atoms. In the eighth O2- site, O2- is bonded in a 3-coordinate geometry to one K1+ and two Te4+ atoms. In the ninth O2- site, O2- is bonded in a 3-coordinate geometry to two K1+ and two Te4+ atoms.