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All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on KNaAl6Si6(HO6)4 by Materials Project

KNaAl6Si6(HO6)4 crystallizes in the monoclinic P2/c space group. The structure is three-dimensional. K1+ is bonded to six O2- atoms to form distorted KO6 octahedra that share corners with four equivalent AlO4 tetrahedra and corners with eight SiO4 tetrahedra. There are a spread of K–O bond distances ranging from 2.78–2.89 Å. Na1+ is bonded to six O2- atoms to form distorted NaO6 octahedra that share corners with two equivalent AlO4 tetrahedra and corners with ten SiO4 tetrahedra. There are a spread of Na–O bond distances ranging from 2.46–3.01 Å. There are three inequivalent Al3+ sites. In the first Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share a cornercorner with one AlO4 tetrahedra, corners with three SiO4 tetrahedra, and edges with three AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.88–1.99 Å. In the second Al3+ site, Al3+ is bonded to four O2- atoms to form AlO4 tetrahedra that share a cornercorner with one NaO6 octahedra, corners with two equivalent KO6 octahedra, corners with two AlO6 octahedra, and corners with three SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 52–72°. There are a spread of Al–O bond distances ranging from 1.75–1.77 Å. In the third Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share a cornercorner with one AlO4 tetrahedra, corners with three SiO4 tetrahedra, and edges with three AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.88–1.99 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 a cornercorner with one NaO6 octahedra, corners with two equivalent KO6 octahedra, corners with two equivalent AlO6 octahedra, a cornercorner with one AlO4 tetrahedra, and corners with two equivalent SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 50–72°. 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 KO6 octahedra, corners with two equivalent NaO6 octahedra, corners with two equivalent AlO6 octahedra, a cornercorner with one SiO4 tetrahedra, and corners with two equivalent AlO4 tetrahedra. The corner-sharing octahedra tilt angles range from 52–67°. There are a spread of Si–O bond distances ranging from 1.62–1.67 Å. In the third Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one KO6 octahedra, corners with two equivalent NaO6 octahedra, corners with two AlO6 octahedra, and corners with three SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 53–72°. There are a spread of Si–O bond distances ranging from 1.62–1.65 Å. There are two inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.97 Å. In the second H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.97 Å. There are twelve inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Al3+ and one Si4+ atom. In the second O2- site, O2- is bonded in a trigonal planar geometry to three Al3+ atoms. In the third O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to two equivalent Al3+ and one H1+ atom. In the fourth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one K1+, one Al3+, and one Si4+ atom. In the fifth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Na1+ and two Si4+ atoms. In the sixth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one K1+ and two Si4+ atoms. In the seventh O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Al3+ and one Si4+ atom. In the eighth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Al3+ and one Si4+ atom. In the ninth O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Al3+ and one H1+ atom. In the tenth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Na1+ and two Si4+ atoms. In the eleventh O2- site, O2- is bonded in a 3-coordinate geometry to one K1+, one Al3+, and one Si4+ atom. In the twelfth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Na1+, one Al3+, and one Si4+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on KNaAl6Si6(HO6)4 by Materials Project

KNaAl6Si6(HO6)4 crystallizes in the monoclinic P2 space group. The structure is three-dimensional. there are two inequivalent K1+ sites. In the first K1+ site, K1+ is bonded to six O2- atoms to form distorted KO6 octahedra that share corners with two equivalent AlO4 tetrahedra and corners with ten SiO4 tetrahedra. There are a spread of K–O bond distances ranging from 2.71–2.89 Å. In the second K1+ site, K1+ is bonded to six O2- atoms to form distorted KO6 octahedra that share corners with four equivalent AlO4 tetrahedra and corners with eight SiO4 tetrahedra. There are a spread of K–O bond distances ranging from 2.79–2.95 Å. There are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded to six O2- atoms to form NaO6 octahedra that share corners with two equivalent AlO4 tetrahedra and corners with ten SiO4 tetrahedra. There are a spread of Na–O bond distances ranging from 2.45–2.86 Å. In the second Na1+ site, Na1+ is bonded to six O2- atoms to form distorted NaO6 octahedra that share corners with four equivalent AlO4 tetrahedra and corners with eight SiO4 tetrahedra. There are a spread of Na–O bond distances ranging from 2.47–2.92 Å. There are six inequivalent Al3+ sites. In the first Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share a cornercorner with one AlO4 tetrahedra, corners with three SiO4 tetrahedra, and edges with three AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.88–1.98 Å. In the second Al3+ site, Al3+ is bonded to four O2- atoms to form AlO4 tetrahedra that share corners with two AlO6 octahedra, corners with three NaO6 octahedra, and corners with three SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 53–71°. There is three shorter (1.76 Å) and one longer (1.78 Å) Al–O bond length. In the third Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share a cornercorner with one AlO4 tetrahedra, corners with three SiO4 tetrahedra, and edges with three AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.88–1.99 Å. In the fourth Al3+ site, Al3+ is bonded to four O2- atoms to form AlO4 tetrahedra that share corners with two AlO6 octahedra, corners with three KO6 octahedra, and corners with three SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 52–70°. There are a spread of Al–O bond distances ranging from 1.74–1.76 Å. In the fifth Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share a cornercorner with one AlO4 tetrahedra, corners with three SiO4 tetrahedra, and edges with three AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.88–1.99 Å. In the sixth Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share a cornercorner with one AlO4 tetrahedra, corners with three SiO4 tetrahedra, and edges with three AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.88–1.99 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 two AlO6 octahedra, corners with three NaO6 octahedra, a cornercorner with one AlO4 tetrahedra, and corners with two equivalent SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 50–70°. There are a spread of Si–O bond distances ranging from 1.62–1.67 Å. In the second Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two AlO6 octahedra, corners with three KO6 octahedra, a cornercorner with one AlO4 tetrahedra, and corners with two equivalent SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 50–72°. There are a spread of Si–O bond distances ranging from 1.61–1.66 Å. In the third Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two AlO6 octahedra, corners with three NaO6 octahedra, a cornercorner with one SiO4 tetrahedra, and corners with two equivalent AlO4 tetrahedra. The corner-sharing octahedra tilt angles range from 52–67°. There are a spread of Si–O bond distances ranging from 1.63–1.67 Å. In the fourth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two AlO6 octahedra, corners with three NaO6 octahedra, and corners with three SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 53–68°. There is one shorter (1.63 Å) and three longer (1.65 Å) Si–O bond length. In the fifth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two AlO6 octahedra, corners with three KO6 octahedra, a cornercorner with one SiO4 tetrahedra, and corners with two equivalent AlO4 tetrahedra. The corner-sharing octahedra tilt angles range from 52–64°. There are a spread of Si–O bond distances ranging from 1.62–1.67 Å. In the sixth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two AlO6 octahedra, corners with three KO6 octahedra, and corners with three SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 53–69°. There is one shorter (1.62 Å) and three longer (1.64 Å) Si–O bond length. There are four inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the second H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the third H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.97 Å. In the fourth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. There are twenty-four inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to two Al3+ and one Si4+ atom. In the second O2- site, O2- is bonded in a trigonal planar geometry to three Al3+ atoms. In the third O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to two Al3+ and one H1+ atom. In the fourth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Na1+, one Al3+, and one Si4+ atom. In the fifth O2- site, O2- is bonded in a 2-coordinate geometry to one Na1+ and two Si4+ atoms. In the sixth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Na1+ and two Si4+ atoms. In the seventh O2- site, O2- is bonded in a distorted trigonal planar geometry to two Al3+ and one Si4+ atom. In the eighth O2- site, O2- is bonded in a trigonal planar geometry to three Al3+ atoms. In the ninth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to two Al3+ and one H1+ atom. In the tenth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one K1+, one Al3+, and one Si4+ atom. In the eleventh O2- site, O2- is bonded in a 2-coordinate geometry to one K1+ and two Si4+ atoms. In the twelfth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one K1+ and two Si4+ atoms. In the thirteenth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Al3+ and one Si4+ atom. In the fourteenth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Al3+ and one Si4+ atom. In the fifteenth O2- site, O2- is bonded in a 3-coordinate geometry to two Al3+ and one H1+ atom. In the sixteenth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Na1+ and two Si4+ atoms. In the seventeenth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Na1+, one Al3+, and one Si4+ atom. In the eighteenth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Na1+, one Al3+, and one Si4+ atom. In the nineteenth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Al3+ and one Si4+ atom. In the twentieth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Al3+ and one Si4+ atom. In the twenty-first O2- site, O2- is bonded in a 3-coordinate geometry to two Al3+ and one H1+ atom. In the twenty-second O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one K1+ and two Si4+ atoms. In the twenty-third O2- site, O2- is bonded in a 3-coordinate geometry to one K1+, one Al3+, and one Si4+ atom. In the twenty-fourth O2- site, O2- is bonded in a distorted trigonal planar geometry to one K1+, one Al3+, and one Si4+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on KNaAl6Si6(HO6)4 by Materials Project

KNaAl6Si6(HO6)4 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are four inequivalent K1+ sites. In the first K1+ site, K1+ is bonded to six O2- atoms to form distorted KO6 octahedra that share corners with two AlO4 tetrahedra and corners with ten SiO4 tetrahedra. There are a spread of K–O bond distances ranging from 2.68–2.87 Å. In the second K1+ site, K1+ is bonded to six O2- atoms to form distorted KO6 octahedra that share corners with four AlO4 tetrahedra and corners with eight SiO4 tetrahedra. There are a spread of K–O bond distances ranging from 2.76–2.88 Å. In the third K1+ site, K1+ is bonded to six O2- atoms to form distorted KO6 octahedra that share corners with four AlO4 tetrahedra and corners with eight SiO4 tetrahedra. There are a spread of K–O bond distances ranging from 2.74–2.91 Å. In the fourth K1+ site, K1+ is bonded to six O2- atoms to form distorted KO6 octahedra that share corners with four AlO4 tetrahedra and corners with eight SiO4 tetrahedra. There are a spread of K–O bond distances ranging from 2.76–2.88 Å. There are four inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded to six O2- atoms to form NaO6 octahedra that share corners with two AlO4 tetrahedra and corners with ten SiO4 tetrahedra. There are a spread of Na–O bond distances ranging from 2.46–2.99 Å. In the second Na1+ site, Na1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Na–O bond distances ranging from 2.57–3.09 Å. In the third Na1+ site, Na1+ is bonded to six O2- atoms to form distorted NaO6 octahedra that share corners with two AlO4 tetrahedra and corners with ten SiO4 tetrahedra. There are a spread of Na–O bond distances ranging from 2.46–3.04 Å. In the fourth Na1+ site, Na1+ is bonded to six O2- atoms to form NaO6 octahedra that share corners with two AlO4 tetrahedra and corners with ten SiO4 tetrahedra. There are a spread of Na–O bond distances ranging from 2.46–2.99 Å. There are twenty-four inequivalent Al3+ sites. In the first Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share a cornercorner with one AlO4 tetrahedra, corners with three SiO4 tetrahedra, and edges with three AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.88–1.99 Å. In the second Al3+ site, Al3+ is bonded to four O2- atoms to form AlO4 tetrahedra that share corners with two KO6 octahedra, corners with two AlO6 octahedra, and corners with three SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 52–71°. There is three shorter (1.75 Å) and one longer (1.77 Å) Al–O bond length. In the third Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share a cornercorner with one AlO4 tetrahedra, corners with three SiO4 tetrahedra, and edges with three AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.88–1.99 Å. In the fourth Al3+ site, Al3+ is bonded to four O2- atoms to form AlO4 tetrahedra that share corners with two KO6 octahedra, corners with two AlO6 octahedra, and corners with three SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 53–71°. There is one shorter (1.75 Å) and three longer (1.76 Å) Al–O bond length. In the fifth Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share a cornercorner with one AlO4 tetrahedra, corners with three SiO4 tetrahedra, and edges with three AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.88–1.99 Å. In the sixth Al3+ site, Al3+ is bonded to four O2- atoms to form AlO4 tetrahedra that share a cornercorner with one NaO6 octahedra, corners with two KO6 octahedra, corners with two AlO6 octahedra, and corners with three SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 52–72°. There is two shorter (1.75 Å) and two longer (1.76 Å) Al–O bond length. In the seventh Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share a cornercorner with one AlO4 tetrahedra, corners with three SiO4 tetrahedra, and edges with three AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.87–1.98 Å. In the eighth Al3+ site, Al3+ is bonded to four O2- atoms to form AlO4 tetrahedra that share a cornercorner with one NaO6 octahedra, corners with two KO6 octahedra, corners with two AlO6 octahedra, and corners with three SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 52–71°. There is two shorter (1.75 Å) and two longer (1.76 Å) Al–O bond length. In the ninth Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share a cornercorner with one AlO4 tetrahedra, corners with three SiO4 tetrahedra, and edges with three AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.88–1.99 Å. In the tenth Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share a cornercorner with one AlO4 tetrahedra, corners with three SiO4 tetrahedra, and edges with three AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.88–1.99 Å. In the eleventh Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share a cornercorner with one AlO4 tetrahedra, corners with three SiO4 tetrahedra, and edges with three AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.88–1.99 Å. In the twelfth Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share a cornercorner with one AlO4 tetrahedra, corners with three SiO4 tetrahedra, and edges with three AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.88–1.99 Å. In the thirteenth Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share a cornercorner with one AlO4 tetrahedra, corners with three SiO4 tetrahedra, and edges with three AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.88–1.99 Å. In the fourteenth Al3+ site, Al3+ is bonded to four O2- atoms to form AlO4 tetrahedra that share a cornercorner with one KO6 octahedra, a cornercorner with one NaO6 octahedra, corners with two AlO6 octahedra, and corners with three SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 53–69°. There is one shorter (1.75 Å) and three longer (1.76 Å) Al–O bond length. In the fifteenth Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share a cornercorner with one AlO4 tetrahedra, corners with three SiO4 tetrahedra, and edges with three AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.87–1.99 Å. In the sixteenth Al3+ site, Al3+ is bonded to four O2- atoms to form AlO4 tetrahedra that share a cornercorner with one KO6 octahedra, a cornercorner with one NaO6 octahedra, corners with two AlO6 octahedra, and corners with three SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 53–70°. There are a spread of Al–O bond distances ranging from 1.74–1.77 Å. In the seventeenth Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share a cornercorner with one AlO4 tetrahedra, corners with three SiO4 tetrahedra, and edges with three AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.88–1.99 Å. In the eighteenth Al3+ site, Al3+ is bonded to four O2- atoms to form AlO4 tetrahedra that share a cornercorner with one NaO6 octahedra, corners with two KO6 octahedra, corners with two AlO6 octahedra, and corners with three SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 52–71°. There is two shorter (1.75 Å) and two longer (1.76 Å) Al–O bond length. In the nineteenth Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share a cornercorner with one AlO4 tetrahedra, corners with three SiO4 tetrahedra, and edges with three AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.88–2.00 Å. In the twentieth Al3+ site, Al3+ is bonded to four O2- atoms to form AlO4 tetrahedra that share a cornercorner with one NaO6 octahedra, corners with two KO6 octahedra, corners with two AlO6 octahedra, and corners with three SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 52–72°. There is two shorter (1.75 Å) and two longer (1.76 Å) Al–O bond length. In the twenty-first Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share a cornercorner with one AlO4 tetrahedra, corners with three SiO4 tetrahedra, and edges with three AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.88–1.98 Å. In the twenty-second Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share a cornercorner with one AlO4 tetrahedra, corners with three SiO4 tetrahedra, and edges with three AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.88–1.99 Å. In the twenty-third Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share a cornercorner with one AlO4 tetrahedra, corners with three SiO4 tetrahedra, and edges with three AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.88–1.98 Å. In the twenty-fourth Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share a cornercorner with one AlO4 tetrahedra, corners with three SiO4 tetrahedra, and edges with three AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.88–1.99 Å. There are twenty-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 KO6 octahedra, corners with two AlO6 octahedra, a cornercorner with one AlO4 tetrahedra, and corners with two SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 50–72°. There are a spread of Si–O bond distances ranging from 1.61–1.67 Å. In the second Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two KO6 octahedra, corners with two AlO6 octahedra, a cornercorner with one AlO4 tetrahedra, and corners with two SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 50–72°. There are a spread of Si–O bond distances ranging from 1.61–1.66 Å. In the third Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one NaO6 octahedra, corners with two KO6 octahedra, corners with two AlO6 octahedra, a cornercorner with one AlO4 tetrahedra, and corners with two SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 51–72°. There are a spread of Si–O bond distances ranging from 1.61–1.66 Å. In the fourth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one NaO6 octahedra, corners with two KO6 octahedra, corners with two AlO6 octahedra, a cornercorner with one AlO4 tetrahedra, and corners with two SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 50–72°. There are a spread of Si–O bond distances ranging from 1.61–1.66 Å. In the fifth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one NaO6 octahedra, corners with two KO6 octahedra, corners with two AlO6 octahedra, a cornercorner with one SiO4 tetrahedra, and corners with two AlO4 tetrahedra. The corner-sharing octahedra tilt angles range from 53–65°. There are a spread of Si–O bond distances ranging from 1.62–1.66 Å. In the sixth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one NaO6 octahedra, corners with two KO6 octahedra, corners with two AlO6 octahedra, and corners with three SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 53–72°. There are a spread of Si–O bond distances ranging from 1.62–1.65 Å. In the seventh Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one KO6 octahedra, a cornercorner with one NaO6 octahedra, corners with two AlO6 octahedra, a cornercorner with one SiO4 tetrahedra, and corners with tw

36 MATERIALS SCIENCE↗