Materials Data on NaBe4SbO7 by Materials Project
NaBe4SbO7 crystallizes in the hexagonal P6_3mc space group. The structure is three-dimensional. Na1+ is bonded to twelve O2- atoms to form NaO12 cuboctahedra that share corners with twelve equivalent NaO12 cuboctahedra, edges with twelve BeO4 tetrahedra, and faces with four equivalent SbO6 octahedra. All Na–O bond lengths are 2.74 Å. There are two inequivalent Be2+ sites. In the first Be2+ site, Be2+ is bonded to four O2- atoms to form BeO4 tetrahedra that share corners with three equivalent SbO6 octahedra, corners with six BeO4 tetrahedra, and edges with three equivalent NaO12 cuboctahedra. The corner-sharing octahedral tilt angles are 57°. There is three shorter (1.65 Å) and one longer (1.67 Å) Be–O bond length. In the second Be2+ site, Be2+ is bonded to four O2- atoms to form BeO4 tetrahedra that share corners with three equivalent SbO6 octahedra, corners with six equivalent BeO4 tetrahedra, and edges with three equivalent NaO12 cuboctahedra. The corner-sharing octahedral tilt angles are 57°. There is three shorter (1.64 Å) and one longer (1.66 Å) Be–O bond length. Sb5+ is bonded to six O2- atoms to form SbO6 octahedra that share corners with twelve BeO4 tetrahedra and faces with four equivalent NaO12 cuboctahedra. All Sb–O bond lengths are 2.00 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Na1+, two Be2+, and one Sb5+ atom. In the second O2- site, O2- is bonded in a tetrahedral geometry to four Be2+ atoms. In the third O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Na1+, two equivalent Be2+, and one Sb5+ atom.