Materials Data on K2BaNa2Ti4Si8(WO7)4 by Materials Project
K2Na2BaTi4Si8(WO7)4 crystallizes in the monoclinic Cm space group. The structure is three-dimensional. there are two inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of K–O bond distances ranging from 2.88–3.45 Å. In the second K1+ site, K1+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of K–O bond distances ranging from 2.75–3.19 Å. Na1+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Na–O bond distances ranging from 2.35–2.56 Å. Ba2+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Ba–O bond distances ranging from 2.77–3.26 Å. There are two inequivalent Ti+2.50+ sites. In the first Ti+2.50+ site, Ti+2.50+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with two equivalent TiO6 octahedra and corners with four SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 41–42°. There are a spread of Ti–O bond distances ranging from 1.89–2.11 Å. In the second Ti+2.50+ site, Ti+2.50+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with two equivalent TiO6 octahedra and corners with four SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 41–42°. There are a spread of Ti–O bond distances ranging from 1.91–2.22 Å. There are two inequivalent W2+ sites. In the first W2+ site, W2+ is bonded in a water-like geometry to two O2- atoms. There are one shorter (2.31 Å) and one longer (2.34 Å) W–O bond lengths. In the second W2+ site, W2+ is bonded in a distorted T-shaped geometry to three O2- atoms. There are a spread of W–O bond distances ranging from 2.15–2.31 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 TiO6 octahedra and corners with two SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 44–55°. 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 TiO6 octahedra and corners with two SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 48–53°. 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 TiO6 octahedra and corners with two SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 38–55°. There are a spread of Si–O bond distances ranging from 1.61–1.65 Å. In the fourth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two TiO6 octahedra and corners with two SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 52–55°. There is three shorter (1.64 Å) and one longer (1.66 Å) Si–O bond length. There are sixteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to one Na1+ and two Si4+ atoms. In the second O2- site, O2- is bonded in a 2-coordinate geometry to one K1+ and two equivalent Si4+ atoms. In the third O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two K1+ and two equivalent Si4+ atoms. In the fourth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one K1+, one Ba2+, one Ti+2.50+, and one Si4+ atom. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to one K1+, one Na1+, one Ti+2.50+, and one Si4+ atom. In the sixth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to two Ti+2.50+ and one W2+ atom. In the seventh O2- site, O2- is bonded in a 4-coordinate geometry to one Na1+, one Ti+2.50+, one W2+, and one Si4+ atom. In the eighth O2- site, O2- is bonded in a 3-coordinate geometry to one Ti+2.50+, one W2+, and one Si4+ atom. In the ninth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one K1+, one Ba2+, and two equivalent Si4+ atoms. In the tenth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two K1+ and two equivalent Si4+ atoms. In the eleventh O2- site, O2- is bonded in a 3-coordinate geometry to one K1+, one Ti+2.50+, one W2+, and one Si4+ atom. In the twelfth O2- site, O2- is bonded in a 2-coordinate geometry to one K1+, one Na1+, one Ti+2.50+, and one Si4+ atom. In the thirteenth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Ba2+ and two Ti+2.50+ atoms. In the fourteenth O2- site, O2- is bonded in a distorted T-shaped geometry to one Na1+ and two Si4+ atoms. In the fifteenth O2- site, O2- is bonded in a 1-coordinate geometry to one K1+, one Ti+2.50+, one W2+, and one Si4+ atom. In the sixteenth O2- site, O2- is bonded in a 3-coordinate geometry to one Ba2+, one Ti+2.50+, and one Si4+ atom.