DOI: 10.17188/1288346
title: Materials Data on Ca8MgAl6Si5O28 by Materials Project

description: Ca8MgAl6Si5O28 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are eight inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Ca–O bond distances ranging from 2.19–2.66 Å. In the second Ca2+ site, Ca2+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Ca–O bond distances ranging from 2.34–2.69 Å. In the third Ca2+ site, Ca2+ is bonded in a 6-coordinate geometry to five O2- atoms. There are a spread of Ca–O bond distances ranging from 2.30–2.63 Å. In the fourth Ca2+ site, Ca2+ is bonded in a 6-coordinate geometry to eight O2- atoms. There are a spread of Ca–O bond distances ranging from 2.25–3.04 Å. In the fifth Ca2+ site, Ca2+ is bonded to seven O2- atoms to form distorted CaO7 pentagonal bipyramids that share a cornercorner with one AlO4 tetrahedra, corners with three SiO4 tetrahedra, a cornercorner with one CaO5 trigonal bipyramid, a cornercorner with one MgO5 trigonal bipyramid, and an edgeedge with one AlO5 trigonal bipyramid. There are a spread of Ca–O bond distances ranging from 2.37–2.93 Å. In the sixth Ca2+ site, Ca2+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Ca–O bond distances ranging from 2.31–2.85 Å. In the seventh Ca2+ site, Ca2+ is bonded to five O2- atoms to form distorted CaO5 trigonal bipyramids that share a cornercorner with one CaO7 pentagonal bipyramid, a cornercorner with one SiO4 tetrahedra, corners with two AlO4 tetrahedra, a cornercorner with one AlO5 trigonal bipyramid, an edgeedge with one SiO4 tetrahedra, and an edgeedge with one AlO5 trigonal bipyramid. There are a spread of Ca–O bond distances ranging from 2.25–2.58 Å. In the eighth Ca2+ site, Ca2+ is bonded in a distorted pentagonal planar geometry to five O2- atoms. There are a spread of Ca–O bond distances ranging from 2.33–2.53 Å. Mg2+ is bonded to five O2- atoms to form distorted MgO5 trigonal bipyramids that share a cornercorner with one CaO7 pentagonal bipyramid, corners with three SiO4 tetrahedra, and an edgeedge with one AlO4 tetrahedra. There are a spread of Mg–O bond distances ranging from 1.90–2.41 Å. There are six inequivalent Al3+ sites. In the first Al3+ site, Al3+ is bonded in a rectangular see-saw-like geometry to four O2- atoms. There are a spread of Al–O bond distances ranging from 1.87–1.95 Å. In the second Al3+ site, Al3+ is bonded to five O2- atoms to form AlO5 trigonal bipyramids that share a cornercorner with one SiO4 tetrahedra, corners with two AlO4 tetrahedra, a cornercorner with one CaO5 trigonal bipyramid, and an edgeedge with one SiO4 tetrahedra. There are a spread of Al–O bond distances ranging from 1.80–2.00 Å. In the third Al3+ site, Al3+ is bonded to five O2- atoms to form AlO5 trigonal bipyramids that share a cornercorner with one AlO4 tetrahedra, a cornercorner with one SiO4 tetrahedra, an edgeedge with one CaO7 pentagonal bipyramid, and an edgeedge with one CaO5 trigonal bipyramid. There are a spread of Al–O bond distances ranging from 1.78–2.05 Å. In the fourth Al3+ site, Al3+ is bonded to four O2- atoms to form AlO4 tetrahedra that share a cornercorner with one CaO7 pentagonal bipyramid, a cornercorner with one AlO5 trigonal bipyramid, and an edgeedge with one MgO5 trigonal bipyramid. There are a spread of Al–O bond distances ranging from 1.75–1.79 Å. In the fifth Al3+ site, Al3+ is bonded to four O2- atoms to form AlO4 tetrahedra that share corners with two SiO4 tetrahedra, a cornercorner with one CaO5 trigonal bipyramid, and a cornercorner with one AlO5 trigonal bipyramid. There are a spread of Al–O bond distances ranging from 1.75–1.79 Å. In the sixth Al3+ site, Al3+ is bonded to four O2- atoms to form AlO4 tetrahedra that share corners with two SiO4 tetrahedra, a cornercorner with one CaO5 trigonal bipyramid, and a cornercorner with one AlO5 trigonal bipyramid. There are a spread of Al–O bond distances ranging from 1.77–1.81 Å. There are five inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one CaO7 pentagonal bipyramid, corners with two AlO4 tetrahedra, and a cornercorner with one MgO5 trigonal bipyramid. There are a spread of Si–O bond distances ranging from 1.63–1.70 Å. In the second Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two AlO5 trigonal bipyramids and an edgeedge with one CaO5 trigonal bipyramid. There are a spread of Si–O bond distances ranging from 1.60–1.69 Å. In the third Si4+ site, Si4+ is bonded in a trigonal non-coplanar geometry to three O2- atoms. There are a spread of Si–O bond distances ranging from 1.67–1.75 Å. In the fourth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one CaO7 pentagonal bipyramid, corners with two AlO4 tetrahedra, and a cornercorner with one MgO5 trigonal bipyramid. There are a spread of Si–O bond distances ranging from 1.59–1.69 Å. In the fifth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one CaO7 pentagonal bipyramid, a cornercorner with one CaO5 trigonal bipyramid, a cornercorner with one MgO5 trigonal bipyramid, and an edgeedge with one AlO5 trigonal bipyramid. There are a spread of Si–O bond distances ranging from 1.62–1.70 Å. There are twenty-eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a water-like geometry to one Al3+ and one Si4+ atom. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ca2+, one Al3+, and one Si4+ atom. In the third O2- site, O2- is bonded in a 4-coordinate geometry to two Ca2+, one Mg2+, and one Al3+ atom. In the fourth O2- site, O2- is bonded in a 2-coordinate geometry to two Ca2+, one Al3+, and one Si4+ atom. In the fifth O2- site, O2- is bonded in a 4-coordinate geometry to two Ca2+ and two Al3+ atoms. In the sixth O2- site, O2- is bonded in a 4-coordinate geometry to two Ca2+ and two Al3+ atoms. In the seventh O2- site, O2- is bonded in a 1-coordinate geometry to four Ca2+ and one Si4+ atom. In the eighth O2- site, O2- is bonded in a 3-coordinate geometry to three Ca2+ and one Al3+ atom. In the ninth O2- site, O2- is bonded in a 4-coordinate geometry to two Ca2+, one Mg2+, and one Al3+ atom. In the tenth O2- site, O2- is bonded in a 4-coordinate geometry to two Ca2+, one Al3+, and one Si4+ atom. In the eleventh O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+, one Mg2+, and one Si4+ atom. In the twelfth O2- site, O2- is bonded in a distorted trigonal pyramidal geometry to three Ca2+ and one Si4+ atom. In the thirteenth O2- site, O2- is bonded in a 1-coordinate geometry to three Ca2+, one Al3+, and one O2- atom. The O–O bond length is 1.51 Å. In the fourteenth O2- site, O2- is bonded in a 1-coordinate geometry to two Ca2+, one Al3+, and one O2- atom. In the fifteenth O2- site, O2- is bonded in a 4-coordinate geometry to two Ca2+, one Al3+, and one Si4+ atom. In the sixteenth O2- site, O2- is bonded in a 4-coordinate geometry to two Ca2+, one Al3+, and one Si4+ atom. In the seventeenth O2- site, O2- is bonded in a 3-coordinate geometry to two Ca2+ and one Si4+ atom. In the eighteenth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ca2+, one Mg2+, and one Si4+ atom. In the nineteenth O2- site, O2- is bonded in a distorted T-shaped geometry to one Ca2+, one Mg2+, and one Si4+ atom. In the twentieth O2- site, O2- is bonded in a 4-coordinate geometry to two Ca2+, one Al3+, and one Si4+ atom. In the twenty-first O2- site, O2- is bonded in a bent 150 degrees geometry to one Al3+ and one Si4+ atom. In the twenty-second O2- site, O2- is bonded in a 4-coordinate geometry to two Ca2+ and two Al3+ atoms. In the twenty-third O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+, one Al3+, and one Si4+ atom. In the twenty-fourth O2- site, O2- is bonded in a 2-coordinate geometry to two Ca2+ and two Al3+ atoms. In the twenty-fifth O2- site, O2- is bonded in a 4-coordinate geometry to two Ca2+, one Al3+, and one Si4+ atom. In the twenty-sixth O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+, one Al3+, and one Si4+ atom. In the twenty-seventh O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ca2+, one Al3+, and one Si4+ atom. In the twenty-eighth O2- site, O2- is bonded in a 4-coordinate geometry to two Ca2+, one Al3+, and one Si4+ atom.