DOI: 10.17188/1290866
title: Materials Data on Mg17(SiO3)16 by Materials Project

description: Mg17(SiO3)16 is Esseneite-derived structured and crystallizes in the monoclinic P2 space group. The structure is three-dimensional. there are thirteen inequivalent Mg sites. In the first Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with six SiO4 tetrahedra and edges with four MgO6 octahedra. There are a spread of Mg–O bond distances ranging from 2.04–2.37 Å. In the second Mg site, Mg is bonded to six O atoms to form distorted MgO6 octahedra that share corners with four SiO4 tetrahedra, edges with three MgO6 octahedra, and edges with two SiO4 tetrahedra. There are a spread of Mg–O bond distances ranging from 2.05–2.44 Å. In the third Mg site, Mg is bonded in a 6-coordinate geometry to six O atoms. There are four shorter (2.08 Å) and two longer (2.47 Å) Mg–O bond lengths. 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 five MgO6 octahedra. There are four shorter (2.04 Å) and two longer (2.31 Å) Mg–O bond lengths. In the fifth Mg site, Mg is bonded to six O atoms to form distorted MgO6 octahedra that share corners with four SiO4 tetrahedra, edges with three MgO6 octahedra, and edges with two equivalent SiO4 tetrahedra. There are a spread of Mg–O bond distances ranging from 2.07–2.41 Å. In the sixth Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with six SiO4 tetrahedra and edges with four MgO6 octahedra. There are a spread of Mg–O bond distances ranging from 2.02–2.20 Å. In the seventh Mg site, Mg is bonded in a 6-coordinate geometry to six O atoms. There are a spread of Mg–O bond distances ranging from 2.01–2.49 Å. In the eighth Mg site, Mg is bonded in a 4-coordinate geometry to four O atoms. There are two shorter (1.97 Å) and two longer (2.03 Å) Mg–O bond lengths. In the ninth Mg site, Mg is bonded to six O atoms to form distorted MgO6 octahedra that share corners with six SiO4 tetrahedra and edges with two equivalent MgO6 octahedra. There are a spread of Mg–O bond distances ranging from 2.05–2.45 Å. In the tenth 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 2.01–2.33 Å. In the eleventh Mg site, Mg is bonded to six O atoms to form distorted MgO6 octahedra that share corners with four SiO4 tetrahedra, edges with three MgO6 octahedra, and edges with two equivalent SiO4 tetrahedra. There are a spread of Mg–O bond distances ranging from 2.04–2.41 Å. In the twelfth Mg site, Mg is bonded in a 6-coordinate geometry to six O atoms. There are a spread of Mg–O bond distances ranging from 2.02–2.60 Å. In the thirteenth 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 2.06–2.27 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 five MgO6 octahedra, corners with two SiO4 tetrahedra, and an edgeedge with one MgO6 octahedra. The corner-sharing octahedra tilt angles range from 31–61°. There are a spread of Si–O bond distances ranging from 1.61–1.69 Å. In the second Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with four MgO6 octahedra, corners with two SiO4 tetrahedra, and an edgeedge with one MgO6 octahedra. The corner-sharing octahedra tilt angles range from 29–60°. There are a spread of Si–O bond distances ranging from 1.62–1.69 Å. In the third Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with four MgO6 octahedra and corners with two SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 33–61°. There are a spread of Si–O bond distances ranging from 1.62–1.69 Å. In the fourth Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with three MgO6 octahedra, corners with two SiO4 tetrahedra, and an edgeedge with one MgO6 octahedra. The corner-sharing octahedra tilt angles range from 32–60°. There are a spread of Si–O bond distances ranging from 1.61–1.68 Å. In the fifth Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with five MgO6 octahedra and corners with two SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 29–61°. There are a spread of Si–O bond distances ranging from 1.62–1.68 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 SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 23–64°. There are a spread of Si–O bond distances ranging from 1.60–1.73 Å. In the seventh Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with four MgO6 octahedra and corners with two SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 33–65°. There are a spread of Si–O bond distances ranging from 1.61–1.75 Å. In the eighth Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with four MgO6 octahedra, corners with two SiO4 tetrahedra, and an edgeedge with one MgO6 octahedra. The corner-sharing octahedra tilt angles range from 31–60°. There are a spread of Si–O bond distances ranging from 1.61–1.68 Å. There are twenty-four inequivalent O sites. In the first O site, O is bonded in a distorted T-shaped geometry to two Mg and one Si atom. In the second O site, O is bonded in a distorted T-shaped geometry to two Mg and one Si atom. In the third O site, O is bonded in a distorted T-shaped geometry to two Mg and one Si atom. In the fourth O site, O is bonded in a distorted T-shaped geometry to two Mg and one Si atom. In the fifth O site, O is bonded in a distorted rectangular see-saw-like geometry to three Mg and one Si atom. In the sixth O site, O is bonded in a distorted rectangular see-saw-like geometry to three Mg and one Si atom. In the seventh O site, O is bonded in a distorted rectangular see-saw-like geometry to three Mg and one Si atom. In the eighth O site, O is bonded to three Mg and one Si atom to form distorted edge-sharing OMg3Si tetrahedra. In the ninth O site, O is bonded in a 2-coordinate geometry to one Mg and two Si atoms. In the tenth O site, O is bonded in a 2-coordinate geometry to one Mg and two Si atoms. In the eleventh O site, O is bonded in a 2-coordinate geometry to one Mg and two Si atoms. In the twelfth O site, O is bonded in a 2-coordinate geometry to one Mg and two Si atoms. In the thirteenth O site, O is bonded in a 2-coordinate geometry to one Mg and two Si atoms. In the fourteenth O site, O is bonded in a 2-coordinate geometry to one Mg and two Si atoms. In the fifteenth O site, O is bonded in a 3-coordinate geometry to one Mg and two Si atoms. In the sixteenth O site, O is bonded in a 4-coordinate geometry to two Mg and two Si atoms. In the seventeenth O site, O is bonded in a distorted rectangular see-saw-like geometry to three Mg and one Si atom. In the eighteenth O site, O is bonded to three Mg and one Si atom to form distorted corner-sharing OMg3Si trigonal pyramids. In the nineteenth 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 twentieth O site, O is bonded in a distorted rectangular see-saw-like geometry to three Mg and one Si atom. In the twenty-first O site, O is bonded in a distorted T-shaped geometry to two Mg and one Si atom. In the twenty-second O site, O is bonded in a distorted rectangular see-saw-like geometry to three Mg and one Si atom. In the twenty-third O site, O is bonded in a distorted T-shaped geometry to two Mg and one Si atom. In the twenty-fourth O site, O is bonded in a distorted trigonal non-coplanar geometry to two Mg and one Si atom.