Materials Data on NaTi2(AsO4)3 by Materials Project
NaTi2(AsO4)3 crystallizes in the trigonal R-3c space group. The structure is three-dimensional. Na1+ is bonded in a distorted hexagonal planar geometry to six equivalent O2- atoms. All Na–O bond lengths are 2.49 Å. Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with six equivalent AsO4 tetrahedra. There is three shorter (1.92 Å) and three longer (2.01 Å) Ti–O bond length. As5+ is bonded to four O2- atoms to form AsO4 tetrahedra that share corners with four equivalent TiO6 octahedra. The corner-sharing octahedra tilt angles range from 26–38°. There is two shorter (1.70 Å) and two longer (1.71 Å) As–O bond length. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 150 degrees geometry to one Ti4+ and one As5+ atom. In the second O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+, one Ti4+, and one As5+ atom.