DOI: 10.17188/1288149
title: Materials Data on Mg21FeSi12(HO16)3 by Materials Project

description: Mg21FeSi12(HO16)3 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are twenty-one inequivalent Mg sites. In the first 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 1.97–2.46 Å. In the second Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with six SiO4 tetrahedra, an edgeedge with one MgO6 octahedra, and an edgeedge with one MgO5 trigonal bipyramid. There are a spread of Mg–O bond distances ranging from 2.10–2.22 Å. In the third Mg site, Mg is bonded in a 5-coordinate geometry to five O atoms. There are a spread of Mg–O bond distances ranging from 1.94–2.09 Å. In the fourth Mg site, Mg is bonded to five O atoms to form distorted MgO5 trigonal bipyramids that share corners with two SiO4 tetrahedra, edges with two MgO6 octahedra, and an edgeedge with one SiO4 tetrahedra. There are a spread of Mg–O bond distances ranging from 1.93–2.35 Å. In the fifth Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with two equivalent MgO6 octahedra, corners with four SiO4 tetrahedra, and edges with seven MgO6 octahedra. The corner-sharing octahedra tilt angles range from 13–16°. There are a spread of Mg–O bond distances ranging from 2.05–2.21 Å. In the sixth Mg site, Mg is bonded to five O atoms to form distorted MgO5 square pyramids that share corners with three SiO4 tetrahedra, corners with two equivalent SiO5 trigonal bipyramids, an edgeedge with one FeO5 square pyramid, and an edgeedge with one MgO5 trigonal bipyramid. There are a spread of Mg–O bond distances ranging from 2.03–2.31 Å. In the seventh Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with two equivalent MgO6 octahedra, corners with four SiO4 tetrahedra, and edges with six MgO6 octahedra. The corner-sharing octahedra tilt angles range from 13–16°. There are a spread of Mg–O bond distances ranging from 2.05–2.46 Å. In the eighth Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with five SiO4 tetrahedra and edges with six MgO6 octahedra. There are a spread of Mg–O bond distances ranging from 2.05–2.11 Å. In the ninth Mg site, Mg is bonded in a 4-coordinate geometry to five O atoms. There are a spread of Mg–O bond distances ranging from 2.03–2.50 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 six MgO6 octahedra. There are a spread of Mg–O bond distances ranging from 2.04–2.38 Å. In the eleventh Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with five SiO4 tetrahedra and edges with five MgO6 octahedra. There are a spread of Mg–O bond distances ranging from 2.03–2.14 Å. In the twelfth Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with two equivalent MgO6 octahedra, corners with four SiO4 tetrahedra, and edges with seven MgO6 octahedra. The corner-sharing octahedra tilt angles range from 13–17°. There are a spread of Mg–O bond distances ranging from 2.05–2.17 Å. In the thirteenth 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 1.97–2.32 Å. In the fourteenth Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with six SiO4 tetrahedra, edges with four MgO6 octahedra, and an edgeedge with one MgO5 trigonal bipyramid. There are a spread of Mg–O bond distances ranging from 2.13–2.28 Å. In the fifteenth Mg site, Mg is bonded in a rectangular see-saw-like geometry to four O atoms. There are a spread of Mg–O bond distances ranging from 1.97–2.03 Å. In the sixteenth Mg site, Mg is bonded in a 5-coordinate geometry to five O atoms. There are a spread of Mg–O bond distances ranging from 1.97–2.51 Å. In the seventeenth Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with two equivalent MgO6 octahedra, corners with four SiO4 tetrahedra, and edges with six MgO6 octahedra. The corner-sharing octahedra tilt angles range from 13–17°. There are a spread of Mg–O bond distances ranging from 2.03–2.30 Å. In the eighteenth Mg site, Mg is bonded in a 5-coordinate geometry to five O atoms. There are a spread of Mg–O bond distances ranging from 1.98–2.26 Å. In the nineteenth Mg site, Mg is bonded to five O atoms to form distorted MgO5 square pyramids that share corners with six SiO4 tetrahedra and an edgeedge with one FeO5 square pyramid. There are a spread of Mg–O bond distances ranging from 2.02–2.19 Å. In the twentieth Mg site, Mg is bonded to five O atoms to form distorted MgO5 trigonal bipyramids that share corners with two equivalent SiO4 tetrahedra, a cornercorner with one SiO5 trigonal bipyramid, and an edgeedge with one MgO5 square pyramid. There are a spread of Mg–O bond distances ranging from 2.05–2.19 Å. In the twenty-first Mg site, Mg is bonded in a 4-coordinate geometry to five O atoms. There are a spread of Mg–O bond distances ranging from 1.96–2.66 Å. Fe is bonded to five O atoms to form FeO5 square pyramids that share corners with three SiO4 tetrahedra, corners with two equivalent SiO5 trigonal bipyramids, and edges with two MgO5 square pyramids. There are a spread of Fe–O bond distances ranging from 1.94–2.19 Å. There are twelve inequivalent Si sites. In the first Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with seven MgO6 octahedra, corners with two SiO4 tetrahedra, and a cornercorner with one MgO5 trigonal bipyramid. The corner-sharing octahedra tilt angles range from 55–61°. There are a spread of Si–O bond distances ranging from 1.64–1.69 Å. In the second Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with ten MgO6 octahedra and a cornercorner with one SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 50–60°. There are a spread of Si–O bond distances ranging from 1.65–1.75 Å. In the third Si site, Si is bonded in a 6-coordinate geometry to six O atoms. There are a spread of Si–O bond distances ranging from 1.72–2.31 Å. In the fourth Si site, Si is bonded to five O atoms to form distorted SiO5 trigonal bipyramids that share a cornercorner with one MgO5 trigonal bipyramid. There are a spread of Si–O bond distances ranging from 1.70–1.98 Å. In the fifth Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with seven MgO6 octahedra, a cornercorner with one SiO4 tetrahedra, and an edgeedge with one MgO5 trigonal bipyramid. The corner-sharing octahedra tilt angles range from 12–79°. There are a spread of Si–O bond distances ranging from 1.63–1.81 Å. In the sixth Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with four MgO6 octahedra and a cornercorner with one MgO5 trigonal bipyramid. The corner-sharing octahedra tilt angles range from 42–63°. There are a spread of Si–O bond distances ranging from 1.63–1.70 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 equivalent MgO5 square pyramids. The corner-sharing octahedra tilt angles range from 48–59°. There are a spread of Si–O bond distances ranging from 1.64–1.70 Å. In the eighth Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with two equivalent FeO5 square pyramids, corners with three MgO5 square pyramids, and a cornercorner with one SiO5 trigonal bipyramid. There are a spread of Si–O bond distances ranging from 1.62–1.69 Å. In the ninth Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with two equivalent MgO5 square pyramids and corners with two equivalent MgO5 trigonal bipyramids. There are a spread of Si–O bond distances ranging from 1.64–1.73 Å. In the tenth Si site, Si is bonded to five O atoms to form SiO5 trigonal bipyramids that share corners with two equivalent MgO5 square pyramids, corners with two equivalent FeO5 square pyramids, and a cornercorner with one SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.68–1.80 Å. In the eleventh Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with four MgO6 octahedra, a cornercorner with one MgO5 square pyramid, a cornercorner with one FeO5 square pyramid, and a cornercorner with one SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 55–63°. There are a spread of Si–O bond distances ranging from 1.62–1.69 Å. In the twelfth Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with eight MgO6 octahedra, a cornercorner with one MgO5 square pyramid, and a cornercorner with one SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 49–56°. There are a spread of Si–O bond distances ranging from 1.61–1.74 Å. There are three inequivalent H sites. In the first H site, H is bonded in a single-bond geometry to one O atom. The H–O bond length is 1.01 Å. In the second H site, H is bonded in a single-bond geometry to one O atom. The H–O bond length is 0.98 Å. In the third H site, H is bonded in a single-bond geometry to one O atom. The H–O bond length is 0.98 Å. There are forty-eight inequivalent O sites. In the first O site, O is bonded to five Mg atoms to form OMg5 square pyramids that share a cornercorner with one OMg3Si tetrahedra and edges with two equivalent OMg5 square pyramids. In the second O site, O is bonded in a rectangular see-saw-like geometry to three Mg and one Si atom. In the third O site, O is bonded in a rectangular see-saw-like geometry to three Mg and one Si atom. In the fourth O site, O is bonded in a 5-coordinate geometry to three Mg and two Si atoms. In the fifth O site, O is bonded in a distorted T-shaped geometry to one Mg and two Si atoms. In the sixth O site, O is bonded in a rectangular see-saw-like geometry to three Mg and one Si atom. In the seventh O site, O is bonded in a trigonal planar geometry to one Mg and two Si atoms. In the eighth O site, O is bonded in a distorted rectangular see-saw-like geometry to three Mg and one Si atom. In the ninth O site, O is bonded to three Mg and one Si atom to form distorted OMg3Si tetrahedra that share a cornercorner with one OMg3FeSi trigonal bipyramid and a cornercorner with one OMg4 trigonal pyramid. In the tenth O site, O is bonded in a distorted T-shaped geometry to two Mg and one Si atom. In the eleventh O site, O is bonded in a 3-coordinate geometry to two Mg and one Si atom. In the twelfth O site, O is bonded in a distorted rectangular see-saw-like geometry to three Mg and one Si atom. In the thirteenth O site, O is bonded in a distorted rectangular see-saw-like geometry to three Mg and one Si atom. In the fourteenth O site, O is bonded in a distorted trigonal planar geometry to two Mg and one Si atom. In the fifteenth O site, O is bonded in a distorted trigonal non-coplanar geometry to one Mg and two Si atoms. In the sixteenth O site, O is bonded to four Mg atoms to form distorted OMg4 trigonal pyramids that share a cornercorner with one OMg3Si tetrahedra, a cornercorner with one OMg5 trigonal bipyramid, and an edgeedge with one OMg5 trigonal bipyramid. In the seventeenth O site, O is bonded in a water-like geometry to two Si atoms. In the eighteenth O site, O is bonded in a 3-coordinate geometry to one Mg, one Si, and one H atom. In the nineteenth O site, O is bonded in a 4-coordinate geometry to three Mg and one Si atom. 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 3-coordinate geometry to one Mg, one Fe, and one Si atom. In the twenty-second O site, O is bonded in a trigonal non-coplanar geometry to two Mg and one Si atom. In the twenty-third O site, O is bonded in a T-shaped geometry to two Mg and one