DOI: 10.17188/1679165
title: Materials Data on KNaSrMg5(SiO3)8 by Materials Project

description: KNaSrMg5(SiO3)8 is Esseneite-derived structured and crystallizes in the triclinic P1 space group. The structure is three-dimensional. K is bonded in a 10-coordinate geometry to ten O atoms. There are a spread of K–O bond distances ranging from 2.72–3.28 Å. Na is bonded in a 8-coordinate geometry to eight O atoms. There are a spread of Na–O bond distances ranging from 2.47–2.87 Å. Sr is bonded in a 8-coordinate geometry to eight O atoms. There are a spread of Sr–O bond distances ranging from 2.49–2.77 Å. There are five inequivalent Mg sites. In the first Mg site, Mg is bonded to six O atoms to form distorted MgO6 octahedra that share corners with four SiO4 tetrahedra and edges with five MgO6 octahedra. There are a spread of Mg–O bond distances ranging from 1.99–2.15 Å. In the second Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with four SiO4 tetrahedra and edges with five MgO6 octahedra. There are a spread of Mg–O bond distances ranging from 2.00–2.15 Å. In the third Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with six SiO4 tetrahedra and edges with three MgO6 octahedra. There are a spread of Mg–O bond distances ranging from 2.02–2.23 Å. In the fourth Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with six SiO4 tetrahedra and edges with three MgO6 octahedra. There are a spread of Mg–O bond distances ranging from 2.06–2.14 Å. In the fifth Mg site, Mg is bonded to six O atoms to form distorted MgO6 octahedra that share corners with four SiO4 tetrahedra and edges with six MgO6 octahedra. There are a spread of Mg–O bond distances ranging from 2.11–2.27 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 corners with three MgO6 octahedra and corners with three SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 57–63°. There are a spread of Si–O bond distances ranging from 1.60–1.67 Å. In the second Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with three MgO6 octahedra and corners with three SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 56–62°. There are a spread of Si–O bond distances ranging from 1.62–1.66 Å. In the third Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with three MgO6 octahedra and corners with three SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 56–62°. There are a spread of Si–O bond distances ranging from 1.62–1.67 Å. In the fourth Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with three MgO6 octahedra and corners with three SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 57–62°. There are a spread of Si–O bond distances ranging from 1.60–1.66 Å. In the fifth Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with three MgO6 octahedra and corners with two equivalent SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 28–55°. There are a spread of Si–O bond distances ranging from 1.60–1.71 Å. In the sixth Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with three MgO6 octahedra and corners with two equivalent SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 34–55°. There are a spread of Si–O bond distances ranging from 1.59–1.69 Å. In the seventh Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with three MgO6 octahedra and corners with two equivalent SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 34–56°. There are a spread of Si–O bond distances ranging from 1.59–1.69 Å. In the eighth Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with three MgO6 octahedra and corners with two equivalent SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 28–56°. There are a spread of Si–O bond distances ranging from 1.60–1.72 Å. There are twenty-four inequivalent O sites. In the first O site, O is bonded in a distorted T-shaped geometry to one Sr, one Mg, and one Si atom. In the second O site, O is bonded in a distorted T-shaped geometry to one Na, one Mg, and one Si atom. In the third O site, O is bonded in a distorted T-shaped geometry to one Na, one Mg, and one Si atom. In the fourth O site, O is bonded in a distorted T-shaped geometry to one Sr, one Mg, and one Si atom. In the fifth O site, O is bonded in a distorted rectangular see-saw-like geometry to one Na, two Mg, and one Si atom. In the sixth O site, O is bonded in a distorted rectangular see-saw-like geometry to one Sr, two Mg, and one Si atom. In the seventh O site, O is bonded in a distorted rectangular see-saw-like geometry to one Sr, two Mg, and one Si atom. In the eighth O site, O is bonded in a distorted rectangular see-saw-like geometry to one Na, two Mg, and one Si atom. In the ninth O site, O is bonded to three Mg and one Si atom to form a mixture of distorted edge and corner-sharing OMg3Si tetrahedra. In the tenth O site, O is bonded to three Mg and one Si atom to form a mixture of distorted edge and corner-sharing OMg3Si trigonal pyramids. In the eleventh O site, O is bonded to three Mg and one Si atom to form a mixture of distorted edge and corner-sharing OMg3Si trigonal pyramids. In the twelfth O site, O is bonded to three Mg and one Si atom to form a mixture of distorted edge and corner-sharing OMg3Si tetrahedra. In the thirteenth O site, O is bonded in a 2-coordinate geometry to one K, one Sr, and two Si atoms. In the fourteenth O site, O is bonded in a 2-coordinate geometry to one K, one Na, and two Si atoms. In the fifteenth O site, O is bonded in a 2-coordinate geometry to one K, one Na, and two Si atoms. In the sixteenth O site, O is bonded in a 2-coordinate geometry to one K, one Sr, and two Si atoms. In the seventeenth O site, O is bonded in a 2-coordinate geometry to one K, one Sr, and two Si atoms. In the eighteenth O site, O is bonded in a 2-coordinate geometry to one K, one Na, and two Si atoms. In the nineteenth O site, O is bonded in a 2-coordinate geometry to one K, one Na, and two Si atoms. In the twentieth O site, O is bonded in a 2-coordinate geometry to one K, one Sr, and two Si atoms. In the twenty-first O site, O is bonded in a 4-coordinate geometry to three Mg and one O atom. The O–O bond length is 1.58 Å. In the twenty-second O site, O is bonded in a 4-coordinate geometry to three Mg and one O atom. In the twenty-third O site, O is bonded in a 2-coordinate geometry to one K and two Si atoms. In the twenty-fourth O site, O is bonded in a 2-coordinate geometry to one K and two Si atoms.