Materials Data on BaNa4Ti2(Si2O5)6 by Materials Project

Na4BaTi2(Si2O5)6 crystallizes in the monoclinic C2/m 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 2.25–2.94 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 2.23–2.64 Å. Ba2+ is bonded in a 10-coordinate geometry to ten O2- atoms. There are a spread of Ba–O bond distances ranging from 2.85–3.25 Å. Ti3+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with four SiO4 tetrahedra and an edgeedge with one TiO6 octahedra. There are a spread of Ti–O bond distances ranging from 1.94–2.17 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 TiO6 octahedra and corners with three SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 46°. There are a spread of Si–O bond distances ranging from 1.58–1.70 Å. In the second Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one TiO6 octahedra and corners with three SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 41°. 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 corner-sharing SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.60–1.66 Å. There are nine inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to one Na1+, one Ba2+, and two equivalent Ti3+ atoms. In the second O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+ and two equivalent Si4+ atoms. In the third O2- site, O2- is bonded in a linear geometry to two equivalent Si4+ atoms. In the fourth O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+, one Ti3+, and one Si4+ atom. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+ and two Si4+ atoms. In the sixth O2- site, O2- is bonded in a 4-coordinate geometry to one Na1+, one Ba2+, one Ti3+, and one Si4+ atom. In the seventh O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Na1+ and two Si4+ atoms. In the eighth O2- site, O2- is bonded in a bent 150 degrees geometry to one Ba2+ and two Si4+ atoms. In the ninth O2- site, O2- is bonded in a 2-coordinate geometry to two Na1+ and two Si4+ atoms.