DOI: 10.17188/1287167
title: Materials Data on K2NaCa2TiSi7HO20 by Materials Project

description: K2NaCa2TiSi7HO20 crystallizes in the triclinic P-1 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 2.84–3.33 Å. In the second K1+ site, K1+ is bonded in a 11-coordinate geometry to one H1+ and ten O2- atoms. The K–H bond length is 2.84 Å. There are a spread of K–O bond distances ranging from 2.83–3.39 Å. Na1+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Na–O bond distances ranging from 2.27–2.81 Å. There are two inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded to six O2- atoms to form CaO6 octahedra that share a cornercorner with one TiO6 octahedra, corners with six SiO4 tetrahedra, and edges with four CaO6 octahedra. The corner-sharing octahedral tilt angles are 58°. There are a spread of Ca–O bond distances ranging from 2.38–2.43 Å. In the second Ca2+ site, Ca2+ is bonded to six O2- atoms to form CaO6 octahedra that share corners with six SiO4 tetrahedra and edges with four CaO6 octahedra. There are a spread of Ca–O bond distances ranging from 2.24–2.42 Å. Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share a cornercorner with one CaO6 octahedra, corners with four SiO4 tetrahedra, and an edgeedge with one TiO6 octahedra. The corner-sharing octahedral tilt angles are 58°. There are a spread of Ti–O bond distances ranging from 1.85–2.18 Å. There are seven inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one TiO6 octahedra, corners with three CaO6 octahedra, and corners with two SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 24–64°. There is two shorter (1.62 Å) and two longer (1.67 Å) Si–O bond length. In the second Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one TiO6 octahedra, corners with three CaO6 octahedra, and corners with two SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 35–63°. There are a spread of Si–O bond distances ranging from 1.61–1.68 Å. In the third Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two CaO6 octahedra and corners with three SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 58–61°. There are a spread of Si–O bond distances ranging from 1.60–1.66 Å. In the fourth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one CaO6 octahedra, a cornercorner with one TiO6 octahedra, and corners with three SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 55–67°. There are a spread of Si–O bond distances ranging from 1.61–1.66 Å. In the fifth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one CaO6 octahedra and corners with three SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 57°. There are a spread of Si–O bond distances ranging from 1.59–1.68 Å. In the sixth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two CaO6 octahedra and corners with three SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 59–64°. There are a spread of Si–O bond distances ranging from 1.60–1.67 Å. In the seventh Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one TiO6 octahedra and corners with two SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 49°. There are a spread of Si–O bond distances ranging from 1.62–1.66 Å. H1+ is bonded in a single-bond geometry to one K1+ and one O2- atom. The H–O bond length is 0.98 Å. There are twenty inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to one K1+ and two Si4+ atoms. In the second O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Na1+, one Ti4+, and one Si4+ atom. In the third O2- site, O2- is bonded in a 4-coordinate geometry to three Ca2+ and one Si4+ atom. In the fourth O2- site, O2- is bonded in a bent 150 degrees geometry to one K1+, one Na1+, and two Si4+ atoms. In the fifth O2- site, O2- is bonded in a 2-coordinate geometry to one K1+, one Na1+, one Ti4+, and one Si4+ atom. In the sixth O2- site, O2- is bonded in a 4-coordinate geometry to three Ca2+ and one Si4+ atom. In the seventh O2- site, O2- is bonded in a 2-coordinate geometry to two K1+ and two Si4+ atoms. In the eighth O2- site, O2- is bonded in a 3-coordinate geometry to one K1+, two Ca2+, and one Si4+ atom. In the ninth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two Si4+ atoms. In the tenth O2- site, O2- is bonded in a 2-coordinate geometry to one K1+ and two Si4+ atoms. In the eleventh O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one K1+ and two Si4+ atoms. In the twelfth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ca2+, one Ti4+, and one Si4+ atom. In the thirteenth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two Si4+ atoms. In the fourteenth O2- site, O2- is bonded in a trigonal planar geometry to one Na1+, one Ca2+, and one Si4+ atom. In the fifteenth O2- site, O2- is bonded in a 2-coordinate geometry to one K1+ and two Si4+ atoms. In the sixteenth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two K1+ and two Si4+ atoms. In the seventeenth O2- site, O2- is bonded in a 3-coordinate geometry to one K1+, two Ca2+, and one Si4+ atom. In the eighteenth O2- site, O2- is bonded in a bent 120 degrees geometry to one K1+, one Si4+, and one H1+ atom. In the nineteenth O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Na1+, one Ti4+, and one Si4+ atom. In the twentieth O2- site, O2- is bonded in a 4-coordinate geometry to one K1+, one Na1+, and two equivalent Ti4+ atoms.