Materials Data on Na2SiBiBO7 by Materials Project
Na2BSiBiO7 crystallizes in the monoclinic P2_1/m space group. The structure is three-dimensional. Na1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Na–O bond distances ranging from 2.20–3.03 Å. B3+ is bonded in a trigonal planar geometry to three O2- atoms. There are a spread of B–O bond distances ranging from 1.32–1.46 Å. Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with four equivalent BiO6 octahedra. The corner-sharing octahedra tilt angles range from 42–54°. There are a spread of Si–O bond distances ranging from 1.63–1.68 Å. Bi5+ is bonded to six O2- atoms to form BiO6 octahedra that share corners with four equivalent SiO4 tetrahedra. There are a spread of Bi–O bond distances ranging from 2.15–2.17 Å. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Na1+ and one B3+ atom. In the second O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two equivalent Na1+, one B3+, and one Bi5+ atom. In the third O2- site, O2- is bonded in a distorted tetrahedral geometry to two equivalent Na1+, one B3+, and one Bi5+ atom. In the fourth O2- site, O2- is bonded in a 1-coordinate geometry to one Na1+, one Si4+, and one Bi5+ atom. In the fifth O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Na1+, one Si4+, and one Bi5+ atom. In the sixth O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Na1+, one Si4+, and one Bi5+ atom.