Materials Data on Na4Bi2As(CO4)4 by Materials Project
Na4Bi2As(CO4)4 crystallizes in the orthorhombic Fddd space group. The structure is three-dimensional. there are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded to six O2- atoms to form distorted NaO6 octahedra that share corners with four equivalent NaO6 octahedra, edges with two equivalent BiO6 octahedra, and an edgeedge with one AsO4 tetrahedra. The corner-sharing octahedra tilt angles range from 56–83°. There are two shorter (2.39 Å) and four longer (2.59 Å) Na–O bond lengths. In the second Na1+ site, Na1+ is bonded to six O2- atoms to form distorted NaO6 octahedra that share corners with four equivalent NaO6 octahedra, edges with two equivalent BiO6 octahedra, and an edgeedge with one AsO4 tetrahedra. The corner-sharing octahedra tilt angles range from 56–83°. There are a spread of Na–O bond distances ranging from 2.39–2.74 Å. C+3.75+ is bonded in a trigonal planar geometry to three O2- atoms. There is two shorter (1.30 Å) and one longer (1.31 Å) C–O bond length. Bi4+ is bonded to six O2- atoms to form BiO6 octahedra that share edges with four NaO6 octahedra. There are a spread of Bi–O bond distances ranging from 2.37–2.39 Å. As5+ is bonded to four equivalent O2- atoms to form AsO4 tetrahedra that share edges with four NaO6 octahedra. All As–O bond lengths are 1.72 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted T-shaped geometry to two Na1+ and one As5+ atom. In the second O2- site, O2- is bonded in a 1-coordinate geometry to one Na1+, one C+3.75+, and one Bi4+ atom. In the third O2- site, O2- is bonded in a distorted single-bond geometry to one Na1+, one C+3.75+, and one Bi4+ atom. In the fourth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two Na1+, one C+3.75+, and one Bi4+ atom.