10.17188/1208036
None Available
Materials Data on NaPrTiNbO6F by Materials Project
LBNL Materials Project; Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
2020
Specialized Mix
36 MATERIALS SCIENCE
crystal structure
NaPrTiNbO6F
F-Na-Nb-O-Pr-Ti
The Materials Project
2020
en
NaPrTiNbO6F crystallizes in the tetragonal P4_122 space group. The structure is three-dimensional. Na1+ is bonded to six O2- and two equivalent F1- atoms to form distorted NaO6F2 hexagonal bipyramids that share edges with two equivalent NaO6F2 hexagonal bipyramids, edges with four equivalent PrO6F2 hexagonal bipyramids, edges with two equivalent TiO6 octahedra, and edges with four equivalent NbO6 octahedra. There are a spread of Na–O bond distances ranging from 2.55–2.82 Å. Both Na–F bond lengths are 2.20 Å. Pr3+ is bonded to six O2- and two equivalent F1- atoms to form distorted PrO6F2 hexagonal bipyramids that share edges with two equivalent PrO6F2 hexagonal bipyramids, edges with four equivalent NaO6F2 hexagonal bipyramids, edges with two equivalent NbO6 octahedra, and edges with four equivalent TiO6 octahedra. There are a spread of Pr–O bond distances ranging from 2.47–2.70 Å. Both Pr–F bond lengths are 2.34 Å. Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with two equivalent TiO6 octahedra, corners with four equivalent NbO6 octahedra, edges with two equivalent NaO6F2 hexagonal bipyramids, and edges with four equivalent PrO6F2 hexagonal bipyramids. The corner-sharing octahedra tilt angles range from 44–48°. There are a spread of Ti–O bond distances ranging from 1.97–2.01 Å. Nb5+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with two equivalent NbO6 octahedra, corners with four equivalent TiO6 octahedra, edges with two equivalent PrO6F2 hexagonal bipyramids, and edges with four equivalent NaO6F2 hexagonal bipyramids. The corner-sharing octahedra tilt angles range from 40–44°. There are a spread of Nb–O bond distances ranging from 2.00–2.02 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to one Na1+, one Pr3+, one Ti4+, and one Nb5+ atom. In the second O2- site, O2- is bonded in a 4-coordinate geometry to one Na1+, one Pr3+, one Ti4+, and one Nb5+ atom. In the third O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Pr3+ and two equivalent Ti4+ atoms. In the fourth O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Na1+ and two equivalent Nb5+ atoms. F1- is bonded to two equivalent Na1+ and two equivalent Pr3+ atoms to form corner-sharing FNa2Pr2 tetrahedra.