DOI: 10.17188/1690704
title: Materials Data on K2Na4Ca5(Si6O17)2 by Materials Project

description: K2Na4Ca5(Si6O17)2 crystallizes in the monoclinic Cm space group. The structure is three-dimensional. there are two inequivalent K sites. In the first K site, K is bonded in a 9-coordinate geometry to nine O atoms. There are a spread of K–O bond distances ranging from 2.76–3.37 Å. In the second K site, K is bonded in a 9-coordinate geometry to seven O atoms. There are a spread of K–O bond distances ranging from 2.78–3.02 Å. There are four inequivalent Na sites. In the first Na site, Na is bonded to six O atoms to form NaO6 octahedra that share a cornercorner with one NaO6 octahedra, a cornercorner with one CaO6 octahedra, corners with four SiO4 tetrahedra, edges with two equivalent NaO6 octahedra, and edges with four CaO6 octahedra. The corner-sharing octahedral tilt angles are 19°. There are a spread of Na–O bond distances ranging from 2.41–2.60 Å. In the second Na site, Na is bonded to six O atoms to form NaO6 octahedra that share a cornercorner with one NaO6 octahedra, a cornercorner with one CaO6 octahedra, corners with four SiO4 tetrahedra, edges with two equivalent NaO6 octahedra, and edges with four CaO6 octahedra. The corner-sharing octahedra tilt angles range from 23–26°. There are a spread of Na–O bond distances ranging from 2.40–2.59 Å. In the third Na site, Na is bonded to six O atoms to form NaO6 octahedra that share corners with two NaO6 octahedra, corners with four SiO4 tetrahedra, and edges with six CaO6 octahedra. The corner-sharing octahedra tilt angles range from 19–26°. There are a spread of Na–O bond distances ranging from 2.37–2.56 Å. In the fourth Na site, Na is bonded in a 4-coordinate geometry to four O atoms. There are two shorter (2.90 Å) and two longer (2.96 Å) Na–O bond lengths. There are three inequivalent Ca sites. In the first Ca site, Ca is bonded to six O atoms to form CaO6 octahedra that share corners with two NaO6 octahedra, corners with four SiO4 tetrahedra, edges with two equivalent NaO6 octahedra, and edges with four CaO6 octahedra. The corner-sharing octahedra tilt angles range from 19–23°. There are a spread of Ca–O bond distances ranging from 2.36–2.41 Å. In the second Ca site, Ca is bonded to six O atoms to form CaO6 octahedra that share corners with four SiO4 tetrahedra, edges with three NaO6 octahedra, and edges with three CaO6 octahedra. There are a spread of Ca–O bond distances ranging from 2.30–2.44 Å. In the third Ca site, Ca is bonded to six O atoms to form CaO6 octahedra that share corners with four SiO4 tetrahedra, edges with three NaO6 octahedra, and edges with three CaO6 octahedra. There are a spread of Ca–O bond distances ranging from 2.32–2.44 Å. There are eight inequivalent Si sites. In the first Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share a cornercorner with one NaO6 octahedra, corners with two CaO6 octahedra, and corners with three SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 50–66°. There are a spread of Si–O bond distances ranging from 1.60–1.68 Å. In the second Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share a cornercorner with one NaO6 octahedra, 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 1.60–1.67 Å. In the third Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with two equivalent CaO6 octahedra and corners with three SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 59°. There are a spread of Si–O bond distances ranging from 1.60–1.67 Å. In the fourth Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with two equivalent CaO6 octahedra and corners with three SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 58°. There is one shorter (1.60 Å) and three longer (1.66 Å) Si–O bond length. In the fifth Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share a cornercorner with one CaO6 octahedra, corners with two NaO6 octahedra, and corners with three SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 51–62°. There are a spread of Si–O bond distances ranging from 1.59–1.68 Å. In the sixth Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share a cornercorner with one CaO6 octahedra, corners with two NaO6 octahedra, and corners with three SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 50–62°. There are a spread of Si–O bond distances ranging from 1.59–1.68 Å. In the seventh Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with two equivalent CaO6 octahedra and corners with three SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 61°. There is one shorter (1.61 Å) and three longer (1.66 Å) Si–O bond length. In the eighth Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with two equivalent CaO6 octahedra and corners with three SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 60°. There is one shorter (1.60 Å) and three longer (1.66 Å) Si–O bond length. There are twenty-four inequivalent O sites. In the first O site, O is bonded in a distorted rectangular see-saw-like geometry to one Na, two Ca, and one Si atom. In the second O site, O is bonded in a distorted rectangular see-saw-like geometry to one Na, two Ca, and one Si atom. In the third O site, O is bonded in a distorted bent 120 degrees geometry to one K, one Na, and two Si atoms. In the fourth O site, O is bonded in a 2-coordinate geometry to one K and two Si atoms. In the fifth O site, O is bonded in a distorted bent 150 degrees geometry to one K and two equivalent Si atoms. In the sixth O site, O is bonded in a 2-coordinate geometry to one K and two equivalent Si atoms. In the seventh O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the eighth O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the ninth O site, O is bonded in a 3-coordinate geometry to one K and two Si atoms. In the tenth O site, O is bonded in a 3-coordinate geometry to one K and two Si atoms. In the eleventh O site, O is bonded in a 1-coordinate geometry to one K, two equivalent Ca, and one Si atom. In the twelfth O site, O is bonded in a distorted trigonal planar geometry to two equivalent Ca and one Si atom. In the thirteenth O site, O is bonded in a 3-coordinate geometry to one K, two equivalent Ca, and one Si atom. In the fourteenth O site, O is bonded in a 3-coordinate geometry to two equivalent Ca and one Si atom. In the fifteenth O site, O is bonded in a distorted bent 120 degrees geometry to one K and two Si atoms. In the sixteenth O site, O is bonded in a distorted bent 120 degrees geometry to one K, one Na, and two Si atoms. In the seventeenth O site, O is bonded in a distorted rectangular see-saw-like geometry to two Na, one Ca, and one Si atom. In the eighteenth O site, O is bonded in a distorted rectangular see-saw-like geometry to two Na, one Ca, and one Si atom. In the nineteenth O site, O is bonded in a see-saw-like geometry to one Na and three Ca atoms. In the twentieth O site, O is bonded in a see-saw-like geometry to two Na and two equivalent Ca atoms. In the twenty-first O site, O is bonded in a see-saw-like geometry to one Na and three Ca atoms. In the twenty-second O site, O is bonded in a see-saw-like geometry to two Na and two equivalent Ca atoms. In the twenty-third O site, O is bonded in a distorted bent 150 degrees geometry to one K and two equivalent Si atoms. In the twenty-fourth O site, O is bonded in a 2-coordinate geometry to one K and two equivalent Si atoms.