Materials Data on K2ZrSi2O7 by Materials Project

Abstract

K2ZrSi2O7 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are six inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of K–O bond distances ranging from 2.87–3.28 Å. In the second K1+ site, K1+ is bonded in a 1-coordinate geometry to one O2- atom. The K–O bond length is 2.48 Å. In the third K1+ site, K1+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of K–O bond distances ranging from 3.01–3.18 Å. In the fourth K1+ site, K1+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of K–O bond distances ranging from 2.67–3.18 Å. In the fifth K1+ site, K1+ is bonded in a 2-coordinate geometry to seven O2- atoms. There are a spread of K–O bond distances ranging from 2.69–3.07 Å. In the sixth K1+ site, K1+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of K–O bond distances ranging from 3.03–3.23 Å. There are three inequivalent Zr4+ sites. In the first Zr4+ site, Zr4+ is bonded to six O2- atoms to form distorted ZrO6 octahedra that share corners with three SiO4 tetrahedra. There are a spread of Zr–O bond distances ranging from 2.07–2.17 Å. In the second Zr4+ site, Zr4+ is bonded to six O2- atoms to form ZrO6 octahedra that share corners with six SiO4 tetrahedra. There are a spread of Zr–O bond distances ranging from 2.10–2.20 Å. In the third Zr4+ site, Zr4+ is bonded to five O2- atoms to form ZrO5 square pyramids that share corners with five SiO4 tetrahedra. There are a spread of Zr–O bond distances ranging from 2.08–2.14 Å. There are six inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two ZrO6 octahedra, a cornercorner with one ZrO5 square pyramid, and a cornercorner with one SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 17–32°. There are a spread of Si–O bond distances ranging from 1.62–1.66 Å. In the second Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one ZrO6 octahedra, a cornercorner with one ZrO5 square pyramid, and a cornercorner with one SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 8°. There are a spread of Si–O bond distances ranging from 1.62–1.67 Å. In the third Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one ZrO6 octahedra, corners with two equivalent ZrO5 square pyramids, and a cornercorner with one SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 7°. There are a spread of Si–O bond distances ranging from 1.62–1.67 Å. In the fourth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one ZrO6 octahedra and corners with two equivalent ZrO5 square pyramids. The corner-sharing octahedral tilt angles are 11°. There is two shorter (1.65 Å) and two longer (1.66 Å) Si–O bond length. In the fifth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one ZrO6 octahedra, corners with two equivalent ZrO5 square pyramids, and a cornercorner with one SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 34°. There is three shorter (1.64 Å) and one longer (1.66 Å) Si–O bond length. In the sixth Si4+ site, Si4+ is bonded in a water-like geometry to two O2- atoms. There is one shorter (1.66 Å) and one longer (1.81 Å) Si–O bond length. There are eighteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted linear geometry to one K1+ and two Si4+ atoms. In the second O2- site, O2- is bonded in a 2-coordinate geometry to two K1+, one Zr4+, and one Si4+ atom. In the third O2- site, O2- is bonded in a distorted linear geometry to two equivalent K1+, one Zr4+, and one Si4+ atom. In the fourth O2- site, O2- is bonded in a distorted linear geometry to one Zr4+ and one Si4+ atom. In the fifth O2- site, O2- is bonded in a distorted single-bond geometry to one K1+, one Si4+, and one O2- atom. The O–O bond length is 1.50 Å. In the sixth O2- site, O2- is bonded in a distorted linear geometry to two K1+, one Zr4+, and one Si4+ atom. In the seventh O2- site, O2- is bonded in a distorted bent 150 degrees geometry to three K1+, one Zr4+, and one Si4+ atom. In the eighth O2- site, O2- is bonded in a bent 150 degrees geometry to two equivalent K1+ and two equivalent Si4+ atoms. In the ninth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two equivalent K1+ and two equivalent Si4+ atoms. In the tenth O2- site, O2- is bonded in a distorted linear geometry to one Zr4+ and one Si4+ atom. In the eleventh O2- site, O2- is bonded in a 2-coordinate geometry to three K1+, one Zr4+, and one Si4+ atom. In the twelfth O2- site, O2- is bonded in a 2-coordinate geometry to two K1+, one Zr4+, and one Si4+ atom. In the thirteenth O2- site, O2- is bonded in a 2-coordinate geometry to two K1+, one Zr4+, and one Si4+ atom. In the fourteenth O2- site, O2- is bonded in a 4-coordinate geometry to two K1+, one Zr4+, and one O2- atom. In the fifteenth O2- site, O2- is bonded in a 2-coordinate geometry to two K1+, one Zr4+, and one Si4+ atom. In the sixteenth O2- site, O2- is bonded in a 2-coordinate geometry to one K1+, one Zr4+, and one Si4+ atom. In the seventeenth O2- site, O2- is bonded in a 2-coordinate geometry to two K1+, one Zr4+, and one Si4+ atom. In the eighteenth O2- site, O2- is bonded in a bent 150 degrees geometry to three K1+ and two Si4+ atoms.