Materials Data on Na5Ni2As(CO4)4 by Materials Project

Na5Ni2As(CO4)4 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. there are three inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded to six O2- atoms to form distorted NaO6 octahedra that share corners with six NaO6 octahedra, edges with two NiO6 octahedra, and an edgeedge with one AsO4 tetrahedra. The corner-sharing octahedra tilt angles range from 57–89°. There are a spread of Na–O bond distances ranging from 2.38–2.56 Å. In the second Na1+ site, Na1+ is bonded to six O2- atoms to form distorted NaO6 octahedra that share corners with six NaO6 octahedra, edges with two NiO6 octahedra, and an edgeedge with one AsO4 tetrahedra. The corner-sharing octahedra tilt angles range from 57–89°. There are a spread of Na–O bond distances ranging from 2.38–2.54 Å. In the third Na1+ site, Na1+ is bonded to six O2- atoms to form distorted NaO6 octahedra that share corners with eight NaO6 octahedra, edges with two equivalent NiO6 octahedra, and an edgeedge with one AsO4 tetrahedra. The corner-sharing octahedra tilt angles range from 61–85°. There are a spread of Na–O bond distances ranging from 2.44–2.51 Å. There are two inequivalent Ni3+ sites. In the first Ni3+ site, Ni3+ is bonded to six O2- atoms to form NiO6 octahedra that share edges with six NaO6 octahedra. There are two shorter (2.08 Å) and four longer (2.09 Å) Ni–O bond lengths. In the second Ni3+ site, Ni3+ is bonded to six O2- atoms to form NiO6 octahedra that share edges with four NaO6 octahedra. There are a spread of Ni–O bond distances ranging from 2.06–2.11 Å. There are two inequivalent C4+ sites. In the first C4+ site, C4+ is bonded in a trigonal planar geometry to three O2- atoms. There is one shorter (1.29 Å) and two longer (1.30 Å) C–O bond length. In the second C4+ site, C4+ is bonded in a trigonal planar geometry to three O2- atoms. There is two shorter (1.29 Å) and one longer (1.30 Å) C–O bond length. As5+ is bonded to four O2- atoms to form AsO4 tetrahedra that share edges with five NaO6 octahedra. There is two shorter (1.72 Å) and two longer (1.73 Å) As–O bond length. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to two Na1+, one Ni3+, and one C4+ atom. In the second O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two Na1+, one Ni3+, and one C4+ atom. In the third O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two Na1+, one Ni3+, and one C4+ atom. In the fourth O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+, one Ni3+, and one C4+ atom. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to two Na1+ and one As5+ atom. In the sixth O2- site, O2- is bonded to three Na1+ and one As5+ atom to form distorted edge-sharing ONa3As trigonal pyramids. In the seventh O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+, one Ni3+, and one C4+ atom. In the eighth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two Na1+, one Ni3+, and one C4+ atom.