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DOE OSTI2020

Materials Data on Al(SiO3)2 by Materials Project

Al(SiO3)2 crystallizes in the monoclinic C2/c space group. The structure is two-dimensional and consists of two Al(SiO3)2 sheets oriented in the (0, 0, 1) direction. Al is bonded to six O atoms to form AlO6 octahedra that share corners with four SiO4 tetrahedra and edges with three equivalent AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.89–1.94 Å. There are two inequivalent Si sites. In the first Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with two equivalent AlO6 octahedra and corners with three equivalent SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 51–55°. There are a spread of Si–O bond distances ranging from 1.62–1.65 Å. In the second Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with two equivalent AlO6 octahedra and corners with three equivalent SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 50–56°. There are a spread of Si–O bond distances ranging from 1.62–1.66 Å. There are six inequivalent O sites. In the first O site, O is bonded in a bent 120 degrees geometry to two equivalent Al atoms. In the second O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the third O site, O is bonded in a distorted bent 120 degrees geometry to two Si atoms. In the fourth O site, O is bonded in a distorted bent 120 degrees geometry to two Si atoms. In the fifth O site, O is bonded in a trigonal planar geometry to two equivalent Al and one Si atom. In the sixth O site, O is bonded in a trigonal planar geometry to two equivalent Al and one Si atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Al(SiO3)2 by Materials Project

Al(SiO3)2 is Low Tridymite-derived structured and crystallizes in the tetragonal I4_1/acd space group. The structure is three-dimensional. Al is bonded to four O atoms to form AlO4 tetrahedra that share corners with four equivalent SiO4 tetrahedra. There is two shorter (1.75 Å) and two longer (1.76 Å) Al–O bond length. Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with two equivalent AlO4 tetrahedra and corners with two equivalent SiO4 tetrahedra. There is two shorter (1.62 Å) and two longer (1.63 Å) Si–O bond length. There are three inequivalent O sites. In the first O site, O is bonded in a bent 150 degrees geometry to one Al and one Si atom. In the second O site, O is bonded in a bent 150 degrees geometry to one Al and one Si atom. In the third O site, O is bonded in a bent 150 degrees geometry to two equivalent Si atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Al(SiO3)2 by Materials Project

Al(SiO3)2 is Low Tridymite-derived structured and crystallizes in the tetragonal P4_32_12 space group. The structure is three-dimensional. Al is bonded to four O atoms to form AlO4 tetrahedra that share corners with four equivalent SiO4 tetrahedra. There is two shorter (1.74 Å) and two longer (1.75 Å) Al–O bond length. Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with two equivalent AlO4 tetrahedra and corners with two equivalent SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.62–1.64 Å. There are three inequivalent O sites. In the first O site, O is bonded in a bent 150 degrees geometry to one Al and one Si atom. In the second O site, O is bonded in a linear geometry to one Al and one Si atom. In the third O site, O is bonded in a bent 150 degrees geometry to two equivalent Si atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Al(SiO3)2 by Materials Project

Al(SiO3)2 is Low Tridymite-derived structured and crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are four inequivalent Al sites. In the first Al site, Al is bonded to four O atoms to form AlO4 tetrahedra that share corners with four SiO4 tetrahedra. There are a spread of Al–O bond distances ranging from 1.74–1.76 Å. In the second Al site, Al is bonded to four O atoms to form AlO4 tetrahedra that share corners with four SiO4 tetrahedra. There is two shorter (1.74 Å) and two longer (1.75 Å) Al–O bond length. In the third Al site, Al is bonded to four O atoms to form AlO4 tetrahedra that share corners with four SiO4 tetrahedra. There is two shorter (1.74 Å) and two longer (1.75 Å) Al–O bond length. In the fourth Al site, Al is bonded to four O atoms to form AlO4 tetrahedra that share corners with four SiO4 tetrahedra. There are a spread of Al–O bond distances ranging from 1.73–1.76 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 two AlO4 tetrahedra and corners with two SiO4 tetrahedra. There is two shorter (1.61 Å) and two longer (1.65 Å) Si–O bond length. In the second Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share a cornercorner with one SiO4 tetrahedra and corners with three AlO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.61–1.65 Å. In the third Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share a cornercorner with one SiO4 tetrahedra and corners with three AlO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.61–1.64 Å. In the fourth Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share a cornercorner with one SiO4 tetrahedra and corners with three AlO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.61–1.64 Å. In the fifth Si site, Si is bonded to four O atoms to form corner-sharing SiO4 tetrahedra. There is one shorter (1.62 Å) and three longer (1.63 Å) Si–O bond length. In the sixth Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share a cornercorner with one SiO4 tetrahedra and corners with three AlO4 tetrahedra. There is three shorter (1.62 Å) and one longer (1.64 Å) Si–O bond length. In the seventh Si site, Si is bonded to four O atoms to form corner-sharing SiO4 tetrahedra. There is one shorter (1.62 Å) and three longer (1.63 Å) Si–O bond length. In the eighth Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with two AlO4 tetrahedra and corners with two SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.61–1.64 Å. There are twenty-four inequivalent O sites. In the first O site, O is bonded in a bent 150 degrees geometry to one Al and one Si atom. In the second O site, O is bonded in a bent 150 degrees geometry to one Al and one Si atom. In the third O site, O is bonded in a bent 150 degrees geometry to one Al and one Si atom. In the fourth O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the fifth O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the sixth O site, O is bonded in a bent 150 degrees geometry to one Al and one Si atom. In the seventh O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the eighth O site, O is bonded in a bent 150 degrees geometry to one Al and one Si atom. In the ninth O site, O is bonded in a bent 150 degrees geometry to one Al and one Si atom. In the tenth O site, O is bonded in a bent 150 degrees geometry to one Al and one Si atom. In the eleventh O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the twelfth O site, O is bonded in a bent 150 degrees geometry to one Al and one Si atom. In the thirteenth O site, O is bonded in a bent 150 degrees geometry to one Al and one Si atom. In the fourteenth O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the fifteenth O site, O is bonded in a bent 150 degrees geometry to one Al and one Si atom. In the sixteenth O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the seventeenth O site, O is bonded in a bent 150 degrees geometry to one Al and one Si atom. In the eighteenth O site, O is bonded in a bent 150 degrees geometry to one Al and one Si atom. In the nineteenth O site, O is bonded in a bent 150 degrees geometry to one Al and one Si atom. In the twentieth O site, O is bonded in a bent 150 degrees geometry to one Al and one Si atom. In the twenty-first O site, O is bonded in a bent 150 degrees geometry to one Al and one Si atom. In the twenty-second O site, O is bonded in a bent 150 degrees geometry to one Al and one Si atom. In the twenty-third O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the twenty-fourth O site, O is bonded in a bent 150 degrees geometry to two Si atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CaAl4(SiO3)8 by Materials Project

Ca(Al(SiO3)2)4 crystallizes in the triclinic P1 space group. The structure is two-dimensional and consists of one calcium molecule and one Al(SiO3)2 sheet oriented in the (0, 0, 1) direction. In the Al(SiO3)2 sheet, there are four inequivalent Al sites. In the first Al site, Al is bonded to six O atoms to form AlO6 octahedra that share corners with four SiO4 tetrahedra and edges with three AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.87–1.96 Å. In the second Al site, Al is bonded to six O atoms to form AlO6 octahedra that share corners with four SiO4 tetrahedra and edges with three AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.86–1.95 Å. In the third Al site, Al is bonded to six O atoms to form AlO6 octahedra that share corners with four SiO4 tetrahedra and edges with three AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.86–1.96 Å. In the fourth Al site, Al is bonded to six O atoms to form AlO6 octahedra that share corners with four SiO4 tetrahedra and edges with three AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.87–1.96 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 two AlO6 octahedra and corners with three SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 51–57°. There are a spread of Si–O bond distances ranging from 1.63–1.65 Å. In the second Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with two AlO6 octahedra and corners with three SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 52–56°. There are a spread of Si–O bond distances ranging from 1.63–1.65 Å. In the third Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with two AlO6 octahedra and corners with three SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 51–56°. There are a spread of Si–O bond distances ranging from 1.63–1.65 Å. In the fourth Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with two AlO6 octahedra and corners with three SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 51–57°. There is one shorter (1.63 Å) and three longer (1.64 Å) Si–O bond length. In the fifth Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with two AlO6 octahedra and corners with three SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 51–57°. There are a spread of Si–O bond distances ranging from 1.63–1.65 Å. In the sixth Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with two AlO6 octahedra and corners with three SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 52–56°. There are a spread of Si–O bond distances ranging from 1.63–1.65 Å. In the seventh Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with two AlO6 octahedra and corners with three SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 52–56°. There is two shorter (1.63 Å) and two longer (1.64 Å) Si–O bond length. In the eighth Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with two AlO6 octahedra and corners with three SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 51–57°. There is one shorter (1.63 Å) and three longer (1.64 Å) Si–O bond length. There are twenty-four inequivalent O sites. In the first O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the second O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the third O site, O is bonded in a trigonal planar geometry to two Al and one Si atom. In the fourth O site, O is bonded in a trigonal planar geometry to two Al and one Si atom. In the fifth O site, O is bonded in a trigonal planar geometry to two Al and one Si atom. In the sixth O site, O is bonded in a trigonal planar geometry to two Al and one Si atom. In the seventh O site, O is bonded in a bent 120 degrees geometry to two Si atoms. In the eighth O site, O is bonded in a bent 120 degrees geometry to two Si atoms. In the ninth O site, O is bonded in a bent 120 degrees geometry to two Si atoms. In the tenth O site, O is bonded in a bent 120 degrees geometry to two Si atoms. In the eleventh O site, O is bonded in a water-like geometry to two Al atoms. In the twelfth O site, O is bonded in a water-like geometry to two Al atoms. In the thirteenth O site, O is bonded in a bent 120 degrees geometry to two Si atoms. In the fourteenth O site, O is bonded in a bent 120 degrees geometry to two Si atoms. In the fifteenth O site, O is bonded in a bent 120 degrees geometry to two Si atoms. In the sixteenth O site, O is bonded in a bent 120 degrees geometry to two Si atoms. In the seventeenth O site, O is bonded in a water-like geometry to two Al atoms. In the eighteenth O site, O is bonded in a water-like geometry to two Al atoms. In the nineteenth O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the twentieth O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the twenty-first O site, O is bonded in a trigonal planar geometry to two Al and one Si atom. In the twenty-second O site, O is bonded in a trigonal planar geometry to two Al and one Si atom. In the twenty-third O site, O is bonded in a trigonal planar geometry to two Al and one Si atom. In the twenty-fourth O site, O is bonded in a trigonal planar geometry to two Al and one Si atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on KAl(SiO3)2 by Materials Project

KAlSi2O6 crystallizes in the tetragonal I4_1/a space group. The structure is three-dimensional. K1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of K–O bond distances ranging from 2.91–3.24 Å. Al3+ is bonded to four O2- atoms to form AlO4 tetrahedra that share corners with four SiO4 tetrahedra. There are a spread of Al–O bond distances ranging from 1.75–1.77 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 two equivalent AlO4 tetrahedra and corners with two equivalent SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.62–1.66 Å. In the second Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two equivalent AlO4 tetrahedra and corners with two equivalent SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.61–1.65 Å. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one K1+, one Al3+, and one Si4+ atom. In the second O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+, one Al3+, and one Si4+ atom. In the third O2- site, O2- is bonded in a bent 150 degrees geometry to one K1+ and two equivalent Si4+ atoms. In the fourth O2- site, O2- is bonded in a 2-coordinate geometry to one K1+ and two equivalent Si4+ atoms. In the fifth O2- site, O2- is bonded in a 2-coordinate geometry to one K1+, one Al3+, and one Si4+ atom. In the sixth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+, one Al3+, and one Si4+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on NaAl(SiO3)2 by Materials Project

NaAlSi2O6 is Esseneite structured and crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. Na1+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Na–O bond distances ranging from 2.39–2.80 Å. Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with six equivalent SiO4 tetrahedra and edges with two equivalent AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.87–2.03 Å. Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with three equivalent AlO6 octahedra and corners with two equivalent SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 32–60°. There are a spread of Si–O bond distances ranging from 1.61–1.66 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Na1+ and two equivalent Si4+ atoms. In the second O2- site, O2- is bonded in a distorted T-shaped geometry to one Na1+, one Al3+, and one Si4+ atom. In the third O2- site, O2- is bonded in a 4-coordinate geometry to one Na1+, two equivalent Al3+, and one Si4+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CsAl(SiO3)2 by Materials Project

CsAlSi2O6 crystallizes in the tetragonal I4_1/acd space group. The structure is three-dimensional. Cs1+ is bonded in a 12-coordinate geometry to twelve O2- atoms. There are a spread of Cs–O bond distances ranging from 3.45–3.68 Å. Al3+ is bonded to four O2- atoms to form AlO4 tetrahedra that share corners with four equivalent SiO4 tetrahedra. There is two shorter (1.75 Å) and two longer (1.76 Å) Al–O bond length. Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two equivalent AlO4 tetrahedra and corners with two equivalent SiO4 tetrahedra. There is two shorter (1.62 Å) and two longer (1.65 Å) Si–O bond length. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 150 degrees geometry to two equivalent Cs1+ and two equivalent Si4+ atoms. In the second O2- site, O2- is bonded in a bent 150 degrees geometry to two equivalent Cs1+, one Al3+, and one Si4+ atom. In the third O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two equivalent Cs1+, one Al3+, and one Si4+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on LiAl(SiO3)2 by Materials Project

LiAlSi2O6 is Esseneite-like structured and crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Li1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Li–O bond distances ranging from 2.09–2.56 Å. Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with six SiO4 tetrahedra and edges with two equivalent AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.84–2.05 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 three equivalent AlO6 octahedra and corners with two equivalent SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 27–60°. There are a spread of Si–O bond distances ranging from 1.60–1.66 Å. In the second Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with three equivalent AlO6 octahedra and corners with two equivalent SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 42–58°. There are a spread of Si–O bond distances ranging from 1.61–1.67 Å. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to one Li1+, one Al3+, and one Si4+ atom. In the second O2- site, O2- is bonded in a 2-coordinate geometry to one Li1+ and two equivalent Si4+ atoms. In the third O2- site, O2- is bonded to one Li1+, two equivalent Al3+, and one Si4+ atom to form a mixture of distorted edge and corner-sharing OLiAl2Si trigonal pyramids. In the fourth O2- site, O2- is bonded in a distorted T-shaped geometry to one Li1+, one Al3+, and one Si4+ atom. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+ and two equivalent Si4+ atoms. In the sixth O2- site, O2- is bonded to one Li1+, two equivalent Al3+, and one Si4+ atom to form a mixture of distorted edge and corner-sharing OLiAl2Si trigonal pyramids.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on LiAl(SiO3)2 by Materials Project

LiAlSi2O6 is Esseneite structured and crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. Li1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Li–O bond distances ranging from 2.11–2.30 Å. Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with six equivalent SiO4 tetrahedra and edges with two equivalent AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.84–2.03 Å. Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with three equivalent AlO6 octahedra and corners with two equivalent SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 30–60°. There are a spread of Si–O bond distances ranging from 1.60–1.66 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+ and two equivalent Si4+ atoms. In the second O2- site, O2- is bonded to one Li1+, two equivalent Al3+, and one Si4+ atom to form a mixture of distorted corner and edge-sharing OLiAl2Si tetrahedra. In the third O2- site, O2- is bonded in a distorted T-shaped geometry to one Li1+, one Al3+, and one Si4+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on NaAl(SiO3)2 by Materials Project

NaAlSi2O6 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. there are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Na–O bond distances ranging from 2.39–3.03 Å. In the second Na1+ site, Na1+ is bonded in a distorted rectangular see-saw-like geometry to four O2- atoms. There are a spread of Na–O bond distances ranging from 2.37–2.44 Å. There are two inequivalent Al3+ sites. In the first Al3+ site, Al3+ is bonded to four O2- atoms to form AlO4 tetrahedra that share corners with four SiO4 tetrahedra. There is three shorter (1.75 Å) and one longer (1.77 Å) Al–O bond length. In the second Al3+ site, Al3+ is bonded to four O2- atoms to form AlO4 tetrahedra that share corners with four SiO4 tetrahedra. There are a spread of Al–O bond distances ranging from 1.74–1.77 Å. There are four inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two equivalent AlO4 tetrahedra and corners with two SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.62–1.66 Å. In the second Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two equivalent AlO4 tetrahedra and corners with two SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.62–1.66 Å. In the third Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two AlO4 tetrahedra and corners with two SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.61–1.67 Å. In the fourth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two AlO4 tetrahedra and corners with two SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.61–1.67 Å. There are twelve inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+, one Al3+, and one Si4+ atom. In the second O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the third O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+, one Al3+, and one Si4+ atom. In the fourth O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the fifth O2- site, O2- is bonded in a 2-coordinate geometry to one Na1+, one Al3+, and one Si4+ atom. In the sixth O2- site, O2- is bonded in a 2-coordinate geometry to one Na1+ and two Si4+ atoms. In the seventh O2- site, O2- is bonded in a 2-coordinate geometry to one Na1+, one Al3+, and one Si4+ atom. In the eighth O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+ and two Si4+ atoms. In the ninth O2- site, O2- is bonded in a 2-coordinate geometry to one Na1+, one Al3+, and one Si4+ atom. In the tenth O2- site, O2- is bonded in a 2-coordinate geometry to one Na1+, one Al3+, and one Si4+ atom. In the eleventh O2- site, O2- is bonded in a bent 150 degrees geometry to one Al3+ and one Si4+ atom. In the twelfth O2- site, O2- is bonded in a bent 150 degrees geometry to one Na1+, one Al3+, and one Si4+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on KAl(SiO3)2 by Materials Project

KAlSi2O6 crystallizes in the orthorhombic C222_1 space group. The structure is three-dimensional. there are two inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 2-coordinate geometry to ten O2- atoms. There are a spread of K–O bond distances ranging from 2.63–3.39 Å. In the second K1+ site, K1+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of K–O bond distances ranging from 2.69–3.09 Å. Al3+ is bonded to four O2- atoms to form AlO4 tetrahedra that share corners with four SiO4 tetrahedra. There are a spread of Al–O bond distances ranging from 1.75–1.77 Å. There are three inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two equivalent AlO4 tetrahedra and corners with two SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.61–1.66 Å. In the second Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two equivalent AlO4 tetrahedra and corners with two equivalent SiO4 tetrahedra. There is two shorter (1.62 Å) and two longer (1.65 Å) Si–O bond length. In the third Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two equivalent AlO4 tetrahedra and corners with two equivalent SiO4 tetrahedra. There is two shorter (1.62 Å) and two longer (1.66 Å) Si–O bond length. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one K1+, one Al3+, and one Si4+ atom. In the second O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one K1+ and two Si4+ atoms. In the third O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+, one Al3+, and one Si4+ atom. In the fourth O2- site, O2- is bonded in a distorted linear geometry to two K1+, one Al3+, and one Si4+ atom. In the fifth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two K1+, one Al3+, and one Si4+ atom. In the sixth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two K1+ and two Si4+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on LiAl(SiO3)2 by Materials Project

LiAlSi2O6 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are two inequivalent Li1+ sites. In the first Li1+ site, Li1+ is bonded in a trigonal non-coplanar geometry to three O2- atoms. There is two shorter (1.93 Å) and one longer (1.94 Å) Li–O bond length. In the second Li1+ site, Li1+ is bonded in a trigonal non-coplanar geometry to three O2- atoms. There are a spread of Li–O bond distances ranging from 1.91–1.94 Å. There are two inequivalent Al3+ sites. In the first Al3+ site, Al3+ is bonded to four O2- atoms to form AlO4 tetrahedra that share corners with four SiO4 tetrahedra. There are a spread of Al–O bond distances ranging from 1.72–1.79 Å. In the second Al3+ site, Al3+ is bonded to four O2- atoms to form AlO4 tetrahedra that share corners with four SiO4 tetrahedra. There is one shorter (1.72 Å) and three longer (1.78 Å) Al–O bond length. There are four 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 AlO4 tetrahedra and corners with three SiO4 tetrahedra. There is one shorter (1.61 Å) and three longer (1.64 Å) Si–O bond length. In the second Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one SiO4 tetrahedra and corners with three AlO4 tetrahedra. There is one shorter (1.63 Å) and three longer (1.64 Å) Si–O bond length. In the third Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one AlO4 tetrahedra and corners with three SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.60–1.64 Å. In the fourth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one SiO4 tetrahedra and corners with three AlO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.63–1.65 Å. There are twelve inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the second O2- site, O2- is bonded in a bent 150 degrees geometry to one Al3+ and one Si4+ atom. In the third O2- site, O2- is bonded in a trigonal planar geometry to one Li1+, one Al3+, and one Si4+ atom. In the fourth O2- site, O2- is bonded in a bent 150 degrees geometry to one Al3+ and one Si4+ atom. In the fifth O2- site, O2- is bonded in a trigonal planar geometry to one Li1+, one Al3+, and one Si4+ atom. In the sixth O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the seventh O2- site, O2- is bonded in a trigonal planar geometry to one Li1+, one Al3+, and one Si4+ atom. In the eighth O2- site, O2- is bonded in a trigonal planar geometry to one Li1+, one Al3+, and one Si4+ atom. In the ninth O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the tenth O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the eleventh O2- site, O2- is bonded in a trigonal planar geometry to one Li1+, one Al3+, and one Si4+ atom. In the twelfth O2- site, O2- is bonded in a trigonal planar geometry to one Li1+, one Al3+, and one Si4+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Na2AlFe(SiO3)4 by Materials Project

Na2FeAl(SiO3)4 is Esseneite-derived structured and crystallizes in the monoclinic C2 space group. The structure is three-dimensional. there are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Na–O bond distances ranging from 2.41–2.84 Å. In the second Na1+ site, Na1+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Na–O bond distances ranging from 2.40–2.85 Å. Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with six SiO4 tetrahedra and edges with two equivalent AlO6 octahedra. There are a spread of Fe–O bond distances ranging from 1.95–2.13 Å. Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with six SiO4 tetrahedra and edges with two equivalent FeO6 octahedra. There are a spread of Al–O bond distances ranging from 1.89–2.05 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 a cornercorner with one FeO6 octahedra, corners with two equivalent AlO6 octahedra, and corners with two equivalent SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 32–62°. There are a spread of Si–O bond distances ranging from 1.61–1.66 Å. In the second Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one AlO6 octahedra, corners with two equivalent FeO6 octahedra, and corners with two equivalent SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 35–60°. There are a spread of Si–O bond distances ranging from 1.61–1.66 Å. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to one Na1+, one Fe3+, one Al3+, and one Si4+ atom. In the second O2- site, O2- is bonded in a 4-coordinate geometry to one Na1+, one Fe3+, one Al3+, and one Si4+ atom. In the third O2- site, O2- is bonded in a distorted T-shaped geometry to one Na1+, one Al3+, and one Si4+ atom. In the fourth O2- site, O2- is bonded in a distorted T-shaped geometry to one Na1+, one Fe3+, and one Si4+ atom. In the fifth O2- site, O2- is bonded in a 2-coordinate geometry to two Na1+ and two Si4+ atoms. In the sixth O2- site, O2- is bonded in a 2-coordinate geometry to two Na1+ and two Si4+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on NaCaMgAl(SiO3)4 by Materials Project

NaCaMgAl(SiO3)4 is Esseneite-derived structured and crystallizes in the monoclinic C2 space group. The structure is three-dimensional. Na1+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Na–O bond distances ranging from 2.41–2.82 Å. Ca2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Ca–O bond distances ranging from 2.37–2.74 Å. Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six SiO4 tetrahedra and edges with two equivalent AlO6 octahedra. There are a spread of Mg–O bond distances ranging from 2.04–2.12 Å. Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with six SiO4 tetrahedra and edges with two equivalent MgO6 octahedra. There are a spread of Al–O bond distances ranging from 1.90–2.08 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 a cornercorner with one AlO6 octahedra, corners with two equivalent MgO6 octahedra, and corners with two equivalent SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 35–61°. There are a spread of Si–O bond distances ranging from 1.60–1.69 Å. In the second Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one MgO6 octahedra, corners with two equivalent AlO6 octahedra, and corners with two equivalent SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 33–63°. 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 3-coordinate geometry to one Ca2+, one Mg2+, and one Si4+ atom. In the second O2- site, O2- is bonded in a distorted T-shaped geometry to one Na1+, one Al3+, and one Si4+ atom. In the third O2- site, O2- is bonded in a 4-coordinate geometry to one Na1+, one Mg2+, one Al3+, and one Si4+ atom. In the fourth O2- site, O2- is bonded in a 4-coordinate geometry to one Ca2+, one Mg2+, one Al3+, and one Si4+ atom. In the fifth O2- site, O2- is bonded in a 2-coordinate geometry to one Na1+, one Ca2+, and two Si4+ atoms. In the sixth O2- site, O2- is bonded in a 2-coordinate geometry to one Na1+, one Ca2+, and two Si4+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Mg2Al3(SiO3)6 by Materials Project

(MgAl(SiO3)3)2Al crystallizes in the orthorhombic Cccm space group. The structure is three-dimensional and consists of four aluminum molecules and one MgAl(SiO3)3 framework. In the MgAl(SiO3)3 framework, Mg is bonded to six O atoms to form distorted MgO6 pentagonal pyramids that share corners with four SiO4 tetrahedra and faces with two equivalent AlO6 pentagonal pyramids. There are two shorter (1.89 Å) and four longer (2.13 Å) Mg–O bond lengths. Al is bonded to six O atoms to form distorted AlO6 pentagonal pyramids that share corners with four SiO4 tetrahedra and faces with two equivalent MgO6 pentagonal pyramids. There are a spread of Al–O bond distances ranging from 1.91–2.01 Å. There are three inequivalent Si sites. In the first Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with two equivalent MgO6 pentagonal pyramids, corners with two equivalent AlO6 pentagonal pyramids, and a cornercorner with one SiO4 tetrahedra. There is three shorter (1.64 Å) and one longer (1.78 Å) Si–O bond length. In the second Si site, Si is bonded in a water-like geometry to two O atoms. Both Si–O bond lengths are 1.64 Å. In the third Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with two equivalent MgO6 pentagonal pyramids, corners with two equivalent AlO6 pentagonal pyramids, and a cornercorner with one SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.64–1.77 Å. There are six inequivalent O sites. In the first O site, O is bonded in a 3-coordinate geometry to one Mg, one Al, and one Si atom. In the second O site, O is bonded in a distorted linear geometry to two Si atoms. In the third O site, O is bonded in a 2-coordinate geometry to one Mg and one Al atom. In the fourth O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the fifth O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the sixth O site, O is bonded in a distorted trigonal planar geometry to one Mg, one Al, and one Si atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on KCa5Mg5Al(SiO3)12 by Materials Project

KCa5Mg5Al(SiO3)12 is Esseneite-derived structured and crystallizes in the monoclinic C2 space group. The structure is three-dimensional. K1+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of K–O bond distances ranging from 2.55–2.81 Å. There are three inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Ca–O bond distances ranging from 2.33–2.78 Å. In the second Ca2+ site, Ca2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Ca–O bond distances ranging from 2.35–2.76 Å. In the third Ca2+ site, Ca2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Ca–O bond distances ranging from 2.36–2.73 Å. There are three inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six SiO4 tetrahedra, an edgeedge with one MgO6 octahedra, and an edgeedge with one AlO6 octahedra. There are a spread of Mg–O bond distances ranging from 2.05–2.20 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 two MgO6 octahedra. There are a spread of Mg–O bond distances ranging from 2.06–2.15 Å. In the third Mg2+ site, Mg2+ is bonded to six O2- atoms to form 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 2.07–2.15 Å. Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with six SiO4 tetrahedra and edges with two equivalent MgO6 octahedra. There is two shorter (1.94 Å) and four longer (1.99 Å) Al–O bond length. There are six 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 MgO6 octahedra, corners with two equivalent AlO6 octahedra, and corners with two SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 30–63°. There are a spread of Si–O bond distances ranging from 1.64–1.69 Å. In the second Si4+ site, Si4+ is bonded to four O2- 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 34–60°. There are a spread of Si–O bond distances ranging from 1.59–1.70 Å. In the third Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one AlO6 octahedra, corners with two equivalent MgO6 octahedra, and corners with two SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 32–63°. There are a spread of Si–O bond distances ranging from 1.60–1.69 Å. In the fourth Si4+ site, Si4+ is bonded to four O2- 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 36–58°. There are a spread of Si–O bond distances ranging from 1.61–1.70 Å. In the fifth Si4+ site, Si4+ is bonded to four O2- 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 33–60°. There are a spread of Si–O bond distances ranging from 1.60–1.71 Å. In the sixth Si4+ site, Si4+ is bonded to four O2- 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 35–59°. There are a spread of Si–O bond distances ranging from 1.60–1.70 Å. There are eighteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to one K1+, one Ca2+, and two Si4+ atoms. In the second O2- site, O2- is bonded in a distorted T-shaped geometry to one Ca2+, one Al3+, and one Si4+ atom. In the third O2- site, O2- is bonded in a 4-coordinate geometry to one K1+, one Mg2+, one Al3+, and one Si4+ atom. In the fourth O2- site, O2- is bonded in a 2-coordinate geometry to one K1+, one Ca2+, and two Si4+ atoms. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to one K1+, one Mg2+, and one Si4+ atom. In the sixth O2- site, O2- is bonded in a 4-coordinate geometry to one Ca2+, two Mg2+, and one Si4+ atom. In the seventh O2- site, O2- is bonded in a 4-coordinate geometry to one Ca2+, one Mg2+, one Al3+, and one Si4+ atom. In the eighth O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+, one Mg2+, and one Si4+ atom. In the ninth O2- site, O2- is bonded in a 2-coordinate geometry to two Ca2+ and two Si4+ atoms. In the tenth O2- site, O2- is bonded in a 2-coordinate geometry to two Ca2+ and two Si4+ atoms. In the eleventh O2- site, O2- is bonded in a distorted T-shaped geometry to one Ca2+, one Mg2+, and one Si4+ atom. In the twelfth O2- site, O2- is bonded in a 4-coordinate geometry to one Ca2+, two Mg2+, and one Si4+ atom. In the thirteenth O2- site, O2- is bonded in a 4-coordinate geometry to one Ca2+, two Mg2+, and one Si4+ atom. In the fourteenth O2- site, O2- is bonded in a distorted T-shaped geometry to one Ca2+, one Mg2+, and one Si4+ atom. In the fifteenth O2- site, O2- is bonded in a 2-coordinate geometry to two Ca2+ and two Si4+ atoms. In the sixteenth O2- site, O2- is bonded in a 2-coordinate geometry to two Ca2+ and two Si4+ atoms. In the seventeenth O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+, one Mg2+, and one Si4+ atom. In the eighteenth O2- site, O2- is bonded in a 4-coordinate geometry to one Ca2+, two Mg2+, and one Si4+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on NaCaAlFe(SiO3)4 by Materials Project

NaCaFeAl(SiO3)4 is Esseneite-derived structured and crystallizes in the monoclinic C2 space group. The structure is three-dimensional. there are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Na–O bond distances ranging from 2.31–2.92 Å. In the second Na1+ site, Na1+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Na–O bond distances ranging from 2.37–2.88 Å. There are two inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Ca–O bond distances ranging from 2.30–2.82 Å. In the second Ca2+ site, Ca2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Ca–O bond distances ranging from 2.32–2.75 Å. There are two inequivalent Fe2+ sites. In the first Fe2+ site, Fe2+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with six SiO4 tetrahedra, an edgeedge with one FeO6 octahedra, and an edgeedge with one AlO6 octahedra. There are a spread of Fe–O bond distances ranging from 2.08–2.20 Å. In the second Fe2+ site, Fe2+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with six SiO4 tetrahedra and edges with two equivalent FeO6 octahedra. There are a spread of Fe–O bond distances ranging from 2.10–2.14 Å. There are two inequivalent Al3+ sites. In the first Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with six SiO4 tetrahedra, an edgeedge with one FeO6 octahedra, and an edgeedge with one AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.92–2.07 Å. In the second Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with six SiO4 tetrahedra and edges with two equivalent AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.88–2.13 Å. There are six inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with three AlO6 octahedra and corners with two SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 30–59°. There are a spread of Si–O bond distances ranging from 1.63–1.68 Å. In the second Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one FeO6 octahedra, corners with two equivalent AlO6 octahedra, and corners with two SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 32–65°. There are a spread of Si–O bond distances ranging from 1.62–1.68 Å. In the third Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with three AlO6 octahedra and corners with two SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 31–59°. There are a spread of Si–O bond distances ranging from 1.62–1.67 Å. In the fourth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with three FeO6 octahedra and corners with two SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 39–60°. There are a spread of Si–O bond distances ranging from 1.59–1.70 Å. In the fifth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one AlO6 octahedra, corners with two equivalent FeO6 octahedra, and corners with two SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 36–65°. There are a spread of Si–O bond distances ranging from 1.59–1.70 Å. In the sixth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with three FeO6 octahedra and corners with two SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 37–61°. There are a spread of Si–O bond distances ranging from 1.60–1.70 Å. There are eighteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to one Na1+, one Ca2+, and two Si4+ atoms. In the second O2- site, O2- is bonded in a distorted T-shaped geometry to one Ca2+, one Al3+, and one Si4+ atom. In the third O2- site, O2- is bonded in a 4-coordinate geometry to one Na1+, two Al3+, and one Si4+ atom. In the fourth O2- site, O2- is bonded in a 4-coordinate geometry to one Na1+, one Fe2+, one Al3+, and one Si4+ atom. In the fifth O2- site, O2- is bonded in a distorted T-shaped geometry to one Na1+, one Al3+, and one Si4+ atom. In the sixth O2- site, O2- is bonded in a 2-coordinate geometry to two Na1+ and two Si4+ atoms. In the seventh O2- site, O2- is bonded in a 2-coordinate geometry to two Na1+ and two Si4+ atoms. In the eighth O2- site, O2- is bonded in a distorted T-shaped geometry to one Na1+, one Al3+, and one Si4+ atom. In the ninth O2- site, O2- is bonded in a 4-coordinate geometry to one Na1+, two Al3+, and one Si4+ atom. In the tenth O2- site, O2- is bonded in a 2-coordinate geometry to one Na1+, one Ca2+, and two Si4+ atoms. In the eleventh O2- site, O2- is bonded in a distorted T-shaped geometry to one Na1+, one Fe2+, and one Si4+ atom. In the twelfth O2- site, O2- is bonded in a 4-coordinate geometry to one Ca2+, two Fe2+, and one Si4+ atom. In the thirteenth O2- site, O2- is bonded in a 4-coordinate geometry to one Ca2+, one Fe2+, one Al3+, and one Si4+ atom. In the fourteenth O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+, one Fe2+, and one Si4+ atom. In the fifteenth O2- site, O2- is bonded in a 2-coordinate geometry to two Ca2+ and two Si4+ atoms. In the sixteenth O2- site, O2- is bonded in a 2-coordinate geometry to two Ca2+ and two Si4+ atoms. In the seventeenth O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+, one Fe2+, and one Si4+ atom. In the eighteenth O2- site, O2- is bonded in a 4-coordinate geometry to one Ca2+, two Fe2+, and one Si4+ atom.

36 MATERIALS SCIENCE↗