Materials Data on Na3Nb34Al2O64 by Materials Project
Na3Al2Nb34O64 crystallizes in the trigonal R-3 space group. The structure is three-dimensional. there are two inequivalent Na sites. In the first Na site, Na is bonded in a 9-coordinate geometry to three equivalent O atoms. All Na–O bond lengths are 2.68 Å. In the second Na site, Na is bonded to twelve O atoms to form NaO12 cuboctahedra that share corners with six equivalent NbO6 octahedra, edges with six equivalent NbO5 square pyramids, and faces with six equivalent NbO6 octahedra. The corner-sharing octahedral tilt angles are 45°. There are six shorter (2.83 Å) and six longer (2.94 Å) Na–O bond lengths. There are seven inequivalent Nb sites. In the first Nb site, Nb is bonded to five O atoms to form NbO5 square pyramids that share corners with three NbO6 octahedra, corners with four NbO5 square pyramids, a cornercorner with one AlO4 tetrahedra, and an edgeedge with one NbO6 octahedra. The corner-sharing octahedra tilt angles range from 3–14°. There are a spread of Nb–O bond distances ranging from 2.04–2.32 Å. In the second Nb site, Nb is bonded to six O atoms to form NbO6 octahedra that share a cornercorner with one NaO12 cuboctahedra, corners with three NbO6 octahedra, corners with three equivalent NbO5 square pyramids, a cornercorner with one AlO4 tetrahedra, edges with three equivalent NbO6 octahedra, and a faceface with one NaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 3–44°. There are a spread of Nb–O bond distances ranging from 2.02–2.24 Å. In the third Nb site, Nb is bonded to six O atoms to form NbO6 octahedra that share corners with three equivalent NbO6 octahedra, corners with three equivalent NbO5 square pyramids, and edges with three equivalent NbO5 square pyramids. The corner-sharing octahedral tilt angles are 44°. There are three shorter (2.03 Å) and three longer (2.05 Å) Nb–O bond lengths. In the fourth Nb site, Nb is bonded to five O atoms to form NbO5 square pyramids that share corners with three equivalent NbO6 octahedra, corners with four NbO5 square pyramids, a cornercorner with one AlO4 tetrahedra, an edgeedge with one NaO12 cuboctahedra, and an edgeedge with one NbO6 octahedra. The corner-sharing octahedra tilt angles range from 43–52°. There are a spread of Nb–O bond distances ranging from 2.07–2.26 Å. In the fifth Nb site, Nb is bonded to five O atoms to form NbO5 square pyramids that share corners with four NbO6 octahedra, corners with four equivalent NbO5 square pyramids, and an edgeedge with one NbO6 octahedra. The corner-sharing octahedra tilt angles range from 6–53°. There are a spread of Nb–O bond distances ranging from 2.06–2.28 Å. In the sixth Nb site, Nb is bonded to six O atoms to form NbO6 octahedra that share a cornercorner with one NbO6 octahedra, corners with five NbO5 square pyramids, edges with two equivalent NbO6 octahedra, and an edgeedge with one NbO5 square pyramid. The corner-sharing octahedral tilt angles are 41°. There are a spread of Nb–O bond distances ranging from 1.96–2.17 Å. In the seventh Nb site, Nb is bonded to six O atoms to form NbO6 octahedra that share corners with three equivalent NbO6 octahedra, corners with three equivalent NbO5 square pyramids, and edges with three equivalent NbO5 square pyramids. The corner-sharing octahedral tilt angles are 41°. There are three shorter (1.98 Å) and three longer (2.11 Å) Nb–O bond lengths. Al is bonded to four O atoms to form AlO4 tetrahedra that share corners with three equivalent NbO6 octahedra and corners with six NbO5 square pyramids. The corner-sharing octahedral tilt angles are 56°. There is three shorter (1.75 Å) and one longer (1.81 Å) Al–O bond length. There are twelve inequivalent O sites. In the first O site, O is bonded in a distorted T-shaped geometry to two Nb and one Al atom. In the second O site, O is bonded in a trigonal non-coplanar geometry to three equivalent Nb atoms. In the third O site, O is bonded in a distorted rectangular see-saw-like geometry to three equivalent Nb and one Al atom. In the fourth O site, O is bonded in a 4-coordinate geometry to one Na and three Nb atoms. In the fifth O site, O is bonded in a T-shaped geometry to three Nb atoms. In the sixth O site, O is bonded in a distorted T-shaped geometry to three Nb atoms. In the seventh O site, O is bonded in a T-shaped geometry to three Nb atoms. In the eighth O site, O is bonded in a distorted trigonal planar geometry to three Nb atoms. In the ninth O site, O is bonded in a 3-coordinate geometry to three Nb atoms. In the tenth O site, O is bonded in a 3-coordinate geometry to one Na and three equivalent Nb atoms. In the eleventh O site, O is bonded in a distorted T-shaped geometry to three Nb atoms. In the twelfth O site, O is bonded to one Na and three Nb atoms to form distorted edge-sharing ONaNb3 trigonal pyramids.