Materials Data on NaTi(SiO3)2 by Materials Project

NaTiSi2O6 is Esseneite structured and crystallizes in the triclinic P-1 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 2.39–2.89 Å. Ti3+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with six SiO4 tetrahedra and edges with two equivalent TiO6 octahedra. There are a spread of Ti–O bond distances ranging from 1.99–2.13 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 TiO6 octahedra and corners with two equivalent SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 30–58°. 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 three equivalent TiO6 octahedra and corners with two equivalent SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 31–57°. 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 distorted T-shaped geometry to one Na1+, one Ti3+, and one Si4+ atom. In the second O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Na1+, two equivalent Ti3+, and one Si4+ atom. In the third O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Na1+ and two Si4+ atoms. In the fourth O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Na1+ and two Si4+ atoms. In the fifth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Na1+, two equivalent Ti3+, and one Si4+ atom. In the sixth O2- site, O2- is bonded in a distorted T-shaped geometry to one Na1+, one Ti3+, and one Si4+ atom.