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Title: Materials Data on Mg7Si8(O11F)2 by Materials Project

Abstract

Mg7Si8O22F2 crystallizes in the orthorhombic Pnnm space group. The structure is three-dimensional. there are four inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded to four O2- and two equivalent F1- atoms to form MgO4F2 octahedra that share corners with four SiO4 tetrahedra and edges with six MgO4F2 octahedra. There are two shorter (2.08 Å) and two longer (2.13 Å) Mg–O bond lengths. Both Mg–F bond lengths are 2.07 Å. In the second Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six SiO4 tetrahedra and edges with five MgO4F2 octahedra. There are a spread of Mg–O bond distances ranging from 2.02–2.18 Å. In the third Mg2+ site, Mg2+ is bonded to six O2- atoms to form distorted MgO6 octahedra that share corners with four SiO4 tetrahedra, edges with three MgO4F2 octahedra, and edges with two equivalent SiO4 tetrahedra. There are a spread of Mg–O bond distances ranging from 2.04–2.44 Å. In the fourth Mg2+ site, Mg2+ is bonded to four equivalent O2- and two equivalent F1- atoms to form MgO4F2 octahedra that share corners with four equivalent SiO4 tetrahedra and edges with six MgO4F2 octahedra. All Mg–O bond lengthsmore » are 2.08 Å. Both Mg–F bond lengths are 2.05 Å. There are two inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with four MgO4F2 octahedra and corners with three SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 57–61°. There are a spread of Si–O bond distances ranging from 1.63–1.65 Å. In the second Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with four MgO4F2 octahedra, corners with two equivalent SiO4 tetrahedra, and an edgeedge with one MgO6 octahedra. The corner-sharing octahedra tilt angles range from 33–60°. There are a spread of Si–O bond distances ranging from 1.61–1.68 Å. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted T-shaped geometry to two Mg2+ and one Si4+ atom. In the second O2- site, O2- is bonded in a 4-coordinate geometry to three Mg2+ and one Si4+ atom. In the third O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to three Mg2+ and one Si4+ atom. In the fourth O2- site, O2- is bonded in a 2-coordinate geometry to one Mg2+ and two Si4+ atoms. In the fifth O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the sixth O2- site, O2- is bonded in a bent 150 degrees geometry to two equivalent Si4+ atoms. F1- is bonded in a distorted trigonal non-coplanar geometry to three Mg2+ atoms.« less

Authors:
Publication Date:
Other Number(s):
mp-559177
DOE Contract Number:  
AC02-05CH11231; EDCBEE
Research Org.:
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). LBNL Materials Project
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES)
Collaborations:
MIT; UC Berkeley; Duke; U Louvain
Subject:
36 MATERIALS SCIENCE
Keywords:
crystal structure; Mg7Si8(O11F)2; F-Mg-O-Si
OSTI Identifier:
1270712
DOI:
https://doi.org/10.17188/1270712

Citation Formats

The Materials Project. Materials Data on Mg7Si8(O11F)2 by Materials Project. United States: N. p., 2020. Web. doi:10.17188/1270712.
The Materials Project. Materials Data on Mg7Si8(O11F)2 by Materials Project. United States. doi:https://doi.org/10.17188/1270712
The Materials Project. 2020. "Materials Data on Mg7Si8(O11F)2 by Materials Project". United States. doi:https://doi.org/10.17188/1270712. https://www.osti.gov/servlets/purl/1270712. Pub date:Thu Apr 30 00:00:00 EDT 2020
@article{osti_1270712,
title = {Materials Data on Mg7Si8(O11F)2 by Materials Project},
author = {The Materials Project},
abstractNote = {Mg7Si8O22F2 crystallizes in the orthorhombic Pnnm space group. The structure is three-dimensional. there are four inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded to four O2- and two equivalent F1- atoms to form MgO4F2 octahedra that share corners with four SiO4 tetrahedra and edges with six MgO4F2 octahedra. There are two shorter (2.08 Å) and two longer (2.13 Å) Mg–O bond lengths. Both Mg–F bond lengths are 2.07 Å. In the second Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six SiO4 tetrahedra and edges with five MgO4F2 octahedra. There are a spread of Mg–O bond distances ranging from 2.02–2.18 Å. In the third Mg2+ site, Mg2+ is bonded to six O2- atoms to form distorted MgO6 octahedra that share corners with four SiO4 tetrahedra, edges with three MgO4F2 octahedra, and edges with two equivalent SiO4 tetrahedra. There are a spread of Mg–O bond distances ranging from 2.04–2.44 Å. In the fourth Mg2+ site, Mg2+ is bonded to four equivalent O2- and two equivalent F1- atoms to form MgO4F2 octahedra that share corners with four equivalent SiO4 tetrahedra and edges with six MgO4F2 octahedra. All Mg–O bond lengths are 2.08 Å. Both Mg–F bond lengths are 2.05 Å. There are two inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with four MgO4F2 octahedra and corners with three SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 57–61°. There are a spread of Si–O bond distances ranging from 1.63–1.65 Å. In the second Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with four MgO4F2 octahedra, corners with two equivalent SiO4 tetrahedra, and an edgeedge with one MgO6 octahedra. The corner-sharing octahedra tilt angles range from 33–60°. There are a spread of Si–O bond distances ranging from 1.61–1.68 Å. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted T-shaped geometry to two Mg2+ and one Si4+ atom. In the second O2- site, O2- is bonded in a 4-coordinate geometry to three Mg2+ and one Si4+ atom. In the third O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to three Mg2+ and one Si4+ atom. In the fourth O2- site, O2- is bonded in a 2-coordinate geometry to one Mg2+ and two Si4+ atoms. In the fifth O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the sixth O2- site, O2- is bonded in a bent 150 degrees geometry to two equivalent Si4+ atoms. F1- is bonded in a distorted trigonal non-coplanar geometry to three Mg2+ atoms.},
doi = {10.17188/1270712},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Thu Apr 30 00:00:00 EDT 2020},
month = {Thu Apr 30 00:00:00 EDT 2020}
}