Materials Data on Na2TiZn2SiO7 by Materials Project
Na2TiZn2SiO7 crystallizes in the orthorhombic Pbca space group. The structure is three-dimensional. there are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a 4-coordinate geometry to four O2- atoms. There are a spread of Na–O bond distances ranging from 2.27–2.50 Å. In the second Na1+ site, Na1+ is bonded in a 4-coordinate geometry to six O2- atoms. There are a spread of Na–O bond distances ranging from 2.34–2.77 Å. Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share a cornercorner with one SiO4 tetrahedra, corners with seven ZnO4 tetrahedra, and edges with two equivalent TiO6 octahedra. There are a spread of Ti–O bond distances ranging from 1.91–2.15 Å. There are two inequivalent Zn2+ sites. In the first Zn2+ site, Zn2+ is bonded to four O2- atoms to form ZnO4 tetrahedra that share corners with four equivalent TiO6 octahedra, a cornercorner with one SiO4 tetrahedra, and corners with two equivalent ZnO4 tetrahedra. The corner-sharing octahedra tilt angles range from 48–62°. There is one shorter (1.97 Å) and three longer (1.98 Å) Zn–O bond length. In the second Zn2+ site, Zn2+ is bonded to four O2- atoms to form ZnO4 tetrahedra that share corners with three equivalent TiO6 octahedra and corners with three equivalent SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 55–65°. There are a spread of Zn–O bond distances ranging from 1.94–2.02 Å. Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one TiO6 octahedra and corners with four ZnO4 tetrahedra. The corner-sharing octahedral tilt angles are 55°. There are a spread of Si–O bond distances ranging from 1.64–1.68 Å. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two equivalent Na1+, one Zn2+, and one Si4+ atom. In the second O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Ti4+ and one Zn2+ atom. In the third O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Na1+, two equivalent Ti4+, and one Zn2+ atom. In the fourth O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Na1+, one Zn2+, and one Si4+ atom. In the fifth O2- site, O2- is bonded to two Na1+, one Zn2+, and one Si4+ atom to form distorted corner-sharing ONa2ZnSi tetrahedra. In the sixth O2- site, O2- is bonded to one Na1+, one Ti4+, one Zn2+, and one Si4+ atom to form distorted ONaTiZnSi trigonal pyramids that share corners with three equivalent ONa2ZnSi tetrahedra and a cornercorner with one ONaTiZn2 trigonal pyramid. In the seventh O2- site, O2- is bonded to one Na1+, one Ti4+, and two equivalent Zn2+ atoms to form distorted ONaTiZn2 trigonal pyramids that share a cornercorner with one ONa2ZnSi tetrahedra and corners with three ONaTiZnSi trigonal pyramids.