DOE OSTI2020
K6Na3Ti2Al2Si8O26Cl3 is Esseneite-derived structured and crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are three inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 8-coordinate geometry to six O2- and two Cl1- atoms. There are a spread of K–O bond distances ranging from 2.82–3.23 Å. There are one shorter (3.12 Å) and one longer (3.17 Å) K–Cl bond lengths. In the second K1+ site, K1+ is bonded in a 8-coordinate geometry to six O2- and two Cl1- atoms. There are a spread of K–O bond distances ranging from 2.82–3.23 Å. There are one shorter (3.12 Å) and one longer (3.17 Å) K–Cl bond lengths. In the third K1+ site, K1+ is bonded in a 7-coordinate geometry to five O2- and two Cl1- atoms. There are a spread of K–O bond distances ranging from 2.97–3.34 Å. There are one shorter (3.24 Å) and one longer (3.27 Å) K–Cl bond lengths. There are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded to four O2- and two equivalent Cl1- atoms to form distorted NaCl2O4 octahedra that share corners with four SiO4 tetrahedra, an edgeedge with one NaCl2O4 octahedra, and edges with two TiO6 octahedra. There are a spread of Na–O bond distances ranging from 2.44–2.46 Å. Both Na–Cl bond lengths are 2.86 Å. In the second Na1+ site, Na1+ is bonded in a 6-coordinate geometry to four O2- and two equivalent Cl1- atoms. All Na–O bond lengths are 2.37 Å. Both Na–Cl bond lengths are 3.12 Å. There are two inequivalent Ti4+ sites. In the first Ti4+ site, Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with six SiO4 tetrahedra and edges with two equivalent NaCl2O4 octahedra. All Ti–O bond lengths are 1.98 Å. In the second Ti4+ site, Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with six SiO4 tetrahedra and edges with two equivalent NaCl2O4 octahedra. All Ti–O bond lengths are 1.98 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 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 NaCl2O4 octahedra, a cornercorner with one TiO6 octahedra, a cornercorner with one AlO4 tetrahedra, and corners with two SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 48–55°. 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 a cornercorner with one NaCl2O4 octahedra, a cornercorner with one TiO6 octahedra, a cornercorner with one AlO4 tetrahedra, and corners with two SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 48–55°. There are a spread of Si–O bond distances ranging from 1.62–1.65 Å. In the third Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one NaCl2O4 octahedra, corners with two TiO6 octahedra, a cornercorner with one AlO4 tetrahedra, and a cornercorner with one SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 44–67°. 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 a cornercorner with one NaCl2O4 octahedra, corners with two TiO6 octahedra, a cornercorner with one AlO4 tetrahedra, and a cornercorner with one SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 44–67°. There are a spread of Si–O bond distances ranging from 1.63–1.67 Å. There are thirteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to two K1+, one Ti4+, and one Si4+ atom. In the second O2- site, O2- is bonded in a 2-coordinate geometry to two K1+, one Ti4+, and one Si4+ atom. In the third O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two K1+ and two Si4+ atoms. In the fourth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two K1+ and two Si4+ atoms. In the fifth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two equivalent K1+, one Al3+, and one Si4+ atom. In the sixth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two equivalent K1+, one Al3+, and one Si4+ atom. In the seventh O2- site, O2- is bonded in a 2-coordinate geometry to one K1+, one Na1+, one Al3+, and one Si4+ atom. In the eighth O2- site, O2- is bonded in a 2-coordinate geometry to one K1+, one Na1+, one Al3+, and one Si4+ atom. In the ninth O2- site, O2- is bonded in a 4-coordinate geometry to one K1+, one Na1+, one Ti4+, and one Si4+ atom. In the tenth O2- site, O2- is bonded in a 4-coordinate geometry to one K1+, one Na1+, one Ti4+, and one Si4+ atom. In the eleventh O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two Si4+ atoms. In the twelfth O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+, one Ti4+, and one Si4+ atom. In the thirteenth O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+, one Ti4+, and one Si4+ atom. There are two inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded in a 6-coordinate geometry to three K1+ and three Na1+ atoms. In the second Cl1- site, Cl1- is bonded in a 6-coordinate geometry to six K1+ atoms.