Materials Data on Na2SiBiCO7 by Materials Project
Na2SiCBiO7 crystallizes in the monoclinic P2_1/m space group. The structure is three-dimensional. Na1+ is bonded to six O2- atoms to form distorted NaO6 octahedra that share corners with two equivalent BiO6 octahedra, corners with three equivalent SiO4 tetrahedra, an edgeedge with one NaO6 octahedra, a faceface with one NaO6 octahedra, and a faceface with one BiO6 octahedra. The corner-sharing octahedra tilt angles range from 63–81°. There are a spread of Na–O bond distances ranging from 2.25–2.60 Å. Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with four equivalent BiO6 octahedra and corners with six equivalent NaO6 octahedra. The corner-sharing octahedra tilt angles range from 48–69°. There is three shorter (1.65 Å) and one longer (1.66 Å) Si–O bond length. C3+ is bonded in a trigonal planar geometry to three O2- atoms. There are a spread of C–O bond distances ranging from 1.25–1.33 Å. Bi5+ is bonded to six O2- atoms to form distorted BiO6 octahedra that share corners with four equivalent NaO6 octahedra, corners with four equivalent SiO4 tetrahedra, and faces with two equivalent NaO6 octahedra. The corner-sharing octahedra tilt angles range from 63–81°. There are a spread of Bi–O bond distances ranging from 2.23–2.38 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 C3+ atom. In the second O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two equivalent Na1+, one C3+, and one Bi5+ atom. In the third O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Na1+, one C3+, 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 distorted rectangular see-saw-like geometry to two equivalent Na1+, one Si4+, and one Bi5+ atom. In the sixth O2- site, O2- is bonded in a distorted tetrahedral geometry to two equivalent Na1+, one Si4+, and one Bi5+ atom.