Materials Data on Na5Ti3O8 by Materials Project
Na5Ti3O8 is Caswellsilverite-like structured and crystallizes in the trigonal R-3m space group. The structure is three-dimensional. there are three inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded to six O2- atoms to form NaO6 octahedra that share corners with six equivalent TiO6 octahedra, edges with four equivalent TiO6 octahedra, and edges with eight NaO6 octahedra. The corner-sharing octahedra tilt angles range from 10–11°. There are two shorter (2.38 Å) and four longer (2.48 Å) Na–O bond lengths. In the second Na1+ site, Na1+ is bonded to six equivalent O2- atoms to form NaO6 octahedra that share corners with six equivalent NaO6 octahedra, edges with six equivalent NaO6 octahedra, and edges with six equivalent TiO6 octahedra. The corner-sharing octahedral tilt angles are 16°. All Na–O bond lengths are 2.23 Å. In the third Na1+ site, Na1+ is bonded to six equivalent O2- atoms to form distorted NaO6 octahedra that share corners with six equivalent NaO6 octahedra, edges with six equivalent NaO6 octahedra, and edges with six equivalent TiO6 octahedra. The corner-sharing octahedral tilt angles are 16°. All Na–O bond lengths are 2.29 Å. Ti+3.67+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with six equivalent NaO6 octahedra, edges with four equivalent TiO6 octahedra, and edges with eight NaO6 octahedra. The corner-sharing octahedra tilt angles range from 10–11°. There are four shorter (2.02 Å) and two longer (2.10 Å) Ti–O bond lengths. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded to three equivalent Na1+ and three equivalent Ti+3.67+ atoms to form ONa3Ti3 octahedra that share corners with six equivalent ONa3Ti3 octahedra and edges with twelve equivalent ONa4Ti2 octahedra. The corner-sharing octahedral tilt angles are 0°. In the second O2- site, O2- is bonded to four Na1+ and two equivalent Ti+3.67+ atoms to form distorted ONa4Ti2 octahedra that share corners with six equivalent ONa4Ti2 octahedra and edges with twelve ONa3Ti3 octahedra. The corner-sharing octahedral tilt angles are 0°.