Materials Data on Na3CuBAsO7 by Materials Project

Abstract

Na3CuBAsO7 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 2.38–2.81 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. Cu3+ is bonded to six O2- atoms to form CuO6 octahedra that share corners with four equivalent AsO4 tetrahedra. There are a spread of Cu–O bond distances ranging from 2.00–2.12 Å. B3+ is bonded in a trigonal planar geometry to three O2- atoms. There is one shorter (1.35 Å) and two longer (1.39 Å) B–O bond length. As5+ is bonded to four O2- atoms to form AsO4 tetrahedra that share corners with four equivalent CuO6 octahedra. The corner-sharing octahedra tilt angles range from 41–59°. There is one shorter (1.70 Å) and three longer (1.74 Å) As–O bond length. 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 1-coordinate geometry to three Na1+, one Cu3+, and one B3+ atom. In the third O2- site, O2- is bonded in a 1-coordinate geometry to three Na1+, one Cu3+, and one B3+ atom. In the fourth O2- site, O2- is bonded in a 4-coordinate geometry to three Na1+, one Cu3+, and one As5+ atom. In the fifth O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Na1+, one Cu3+, and one As5+ atom. In the sixth O2- site, O2- is bonded in a rectangular see-saw-like geometry to two equivalent Na1+, one Cu3+, and one As5+ atom.