Materials Data on Na2VO4 by Materials Project
Na2VO4 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are four inequivalent Na sites. In the first Na site, Na is bonded to six O atoms to form distorted NaO6 octahedra that share a cornercorner with one NaO6 octahedra, corners with two equivalent NaO5 square pyramids, corners with two VO4 tetrahedra, corners with three equivalent NaO5 trigonal bipyramids, edges with three NaO6 octahedra, and an edgeedge with one VO4 tetrahedra. The corner-sharing octahedral tilt angles are 13°. There are a spread of Na–O bond distances ranging from 2.36–2.56 Å. In the second Na site, Na is bonded to five O atoms to form NaO5 trigonal bipyramids that share corners with three equivalent NaO6 octahedra, corners with five VO4 tetrahedra, edges with two equivalent NaO6 octahedra, and an edgeedge with one NaO5 square pyramid. The corner-sharing octahedra tilt angles range from 68–81°. There are a spread of Na–O bond distances ranging from 2.33–2.59 Å. In the third Na site, Na is bonded to five O atoms to form distorted NaO5 square pyramids that share corners with four NaO6 octahedra, corners with five VO4 tetrahedra, an edgeedge with one NaO5 square pyramid, an edgeedge with one VO4 tetrahedra, and an edgeedge with one NaO5 trigonal bipyramid. The corner-sharing octahedra tilt angles range from 54–80°. There are a spread of Na–O bond distances ranging from 2.28–2.55 Å. In the fourth Na site, Na is bonded to six O atoms to form distorted NaO6 octahedra that share a cornercorner with one NaO6 octahedra, corners with two equivalent NaO5 square pyramids, corners with five VO4 tetrahedra, edges with two equivalent NaO6 octahedra, and edges with two equivalent NaO5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 13°. There are a spread of Na–O bond distances ranging from 2.32–2.64 Å. There are two inequivalent V sites. In the first V site, V is bonded to four O atoms to form VO4 tetrahedra that share corners with three NaO6 octahedra, corners with four equivalent NaO5 square pyramids, a cornercorner with one VO4 tetrahedra, corners with two equivalent NaO5 trigonal bipyramids, and an edgeedge with one NaO6 octahedra. The corner-sharing octahedra tilt angles range from 55–59°. There is three shorter (1.72 Å) and one longer (1.87 Å) V–O bond length. In the second V site, V is bonded to four O atoms to form VO4 tetrahedra that share corners with four NaO6 octahedra, a cornercorner with one NaO5 square pyramid, a cornercorner with one VO4 tetrahedra, corners with three equivalent NaO5 trigonal bipyramids, and an edgeedge with one NaO5 square pyramid. The corner-sharing octahedra tilt angles range from 47–68°. There are a spread of V–O bond distances ranging from 1.70–1.86 Å. There are eight inequivalent O sites. In the first O site, O is bonded to three Na and one V atom to form a mixture of distorted edge and corner-sharing ONa3V trigonal pyramids. In the second O site, O is bonded in a distorted rectangular see-saw-like geometry to two equivalent Na and two V atoms. In the third O site, O is bonded in a distorted trigonal planar geometry to two Na and one V atom. In the fourth O site, O is bonded in a distorted see-saw-like geometry to three Na and one V atom. In the fifth O site, O is bonded to three Na and one V atom to form distorted corner-sharing ONa3V trigonal pyramids. In the sixth O site, O is bonded in a distorted T-shaped geometry to three Na atoms. In the seventh O site, O is bonded in a 4-coordinate geometry to three Na and one V atom. In the eighth O site, O is bonded to three Na and one V atom to form a mixture of distorted edge and corner-sharing ONa3V trigonal pyramids.