Materials Data on Mg3AlFe(SiO4)3 by Materials Project
Mg3FeAl(SiO4)3 crystallizes in the monoclinic P2_1 space group. The structure is three-dimensional. there are three inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Mg–O bond distances ranging from 2.03–2.61 Å. In the second Mg2+ site, Mg2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Mg–O bond distances ranging from 2.04–2.62 Å. In the third Mg2+ site, Mg2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Mg–O bond distances ranging from 2.05–2.47 Å. Fe3+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Fe–O bond distances ranging from 2.02–2.45 Å. Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with six SiO6 octahedra. The corner-sharing octahedra tilt angles range from 35–38°. There are a spread of Al–O bond distances ranging from 1.87–1.95 Å. There are three inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded to six O2- atoms to form SiO6 octahedra that share a cornercorner with one AlO6 octahedra and corners with five equivalent SiO6 octahedra. The corner-sharing octahedra tilt angles range from 32–35°. There are a spread of Si–O bond distances ranging from 1.77–1.85 Å. In the second Si4+ site, Si4+ is bonded to six O2- atoms to form corner-sharing SiO6 octahedra. The corner-sharing octahedra tilt angles range from 32–37°. There are a spread of Si–O bond distances ranging from 1.81–1.84 Å. In the third Si4+ site, Si4+ is bonded to six O2- atoms to form SiO6 octahedra that share a cornercorner with one SiO6 octahedra and corners with five equivalent AlO6 octahedra. The corner-sharing octahedra tilt angles range from 35–38°. There are a spread of Si–O bond distances ranging from 1.75–1.86 Å. There are twelve inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to one Mg2+, two equivalent Fe3+, one Al3+, and one Si4+ atom. In the second O2- site, O2- is bonded in a 5-coordinate geometry to one Mg2+, two equivalent Fe3+, one Al3+, and one Si4+ atom. In the third O2- site, O2- is bonded to two equivalent Mg2+ and two Si4+ atoms to form distorted corner-sharing OMg2Si2 tetrahedra. In the fourth O2- site, O2- is bonded to two equivalent Fe3+, one Al3+, and one Si4+ atom to form distorted OAlFe2Si trigonal pyramids that share corners with two OMg2AlSi tetrahedra and corners with two equivalent OAlFe2Si trigonal pyramids. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to two Mg2+, one Fe3+, one Al3+, and one Si4+ atom. In the sixth O2- site, O2- is bonded in a 5-coordinate geometry to three Mg2+ and two Si4+ atoms. In the seventh O2- site, O2- is bonded in a 5-coordinate geometry to three Mg2+ and two Si4+ atoms. In the eighth O2- site, O2- is bonded in a 5-coordinate geometry to two Mg2+, one Fe3+, one Al3+, and one Si4+ atom. In the ninth O2- site, O2- is bonded to two Mg2+, one Al3+, and one Si4+ atom to form distorted OMg2AlSi tetrahedra that share corners with three OMg2Si2 tetrahedra and a cornercorner with one OAlFe2Si trigonal pyramid. In the tenth O2- site, O2- is bonded to two Mg2+ and two Si4+ atoms to form distorted OMg2Si2 tetrahedra that share corners with three OMg2Si2 tetrahedra and a cornercorner with one OAlFe2Si trigonal pyramid. In the eleventh O2- site, O2- is bonded in a 5-coordinate geometry to three Mg2+ and two Si4+ atoms. In the twelfth O2- site, O2- is bonded in a 5-coordinate geometry to three Mg2+ and two Si4+ atoms.