Materials Data on Na3FeBAsO7 by Materials Project
Na3FeBAsO7 crystallizes in the monoclinic P2_1/m space group. The structure is three-dimensional. there are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Na–O bond distances ranging from 2.34–2.87 Å. In the second Na1+ site, Na1+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Na–O bond distances ranging from 2.26–2.93 Å. Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with four equivalent AsO4 tetrahedra. There are a spread of Fe–O bond distances ranging from 2.00–2.10 Å. B3+ is bonded in a trigonal planar geometry to three O2- atoms. There are a spread of B–O bond distances ranging from 1.35–1.42 Å. As5+ is bonded to four O2- atoms to form AsO4 tetrahedra that share corners with four equivalent FeO6 octahedra. The corner-sharing octahedra tilt angles range from 39–54°. There are a spread of As–O bond distances ranging from 1.71–1.74 Å. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded in a 5-coordinate geometry to four Na1+ and one B3+ atom. In the second O2- site, O2- is bonded in a 5-coordinate geometry to three Na1+, one Fe3+, and one B3+ atom. In the third O2- site, O2- is bonded in a 5-coordinate geometry to three Na1+, one Fe3+, and one B3+ atom. In the fourth O2- site, O2- is bonded in a 5-coordinate geometry to three Na1+, one Fe3+, and one As5+ atom. In the fifth O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Na1+, one Fe3+, and one As5+ atom. In the sixth O2- site, O2- is bonded in a rectangular see-saw-like geometry to two equivalent Na1+, one Fe3+, and one As5+ atom.