Materials Data on Sr3Ta6(Si2O13)2 by Materials Project

Sr3Ta6(Si2O13)2 crystallizes in the hexagonal P-62m space group. The structure is three-dimensional. Sr2+ is bonded in a 12-coordinate geometry to twelve O2- atoms. There are a spread of Sr–O bond distances ranging from 2.76–3.16 Å. Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with four equivalent TaO6 octahedra and corners with two equivalent SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 9–36°. There are a spread of Ta–O bond distances ranging from 1.94–2.06 Å. Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with three equivalent TaO6 octahedra and a cornercorner with one SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 34°. There is one shorter (1.62 Å) and three longer (1.63 Å) Si–O bond length. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a linear geometry to two equivalent Sr2+ and two equivalent Ta5+ atoms. In the second O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Sr2+, one Ta5+, and one Si4+ atom. 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 bent 150 degrees geometry to two equivalent Ta5+ atoms. In the fifth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Sr2+ and two equivalent Ta5+ atoms.