Materials Data on NaTa7O19 by Materials Project
NaTa7O19 crystallizes in the orthorhombic Pbam space group. The structure is three-dimensional. Na is bonded in a 9-coordinate geometry to nine O atoms. There are a spread of Na–O bond distances ranging from 2.64–2.99 Å. There are seven inequivalent Ta sites. In the first Ta site, Ta is bonded to six O atoms to form TaO6 octahedra that share corners with six TaO6 octahedra and an edgeedge with one TaO7 pentagonal bipyramid. The corner-sharing octahedra tilt angles range from 11–40°. There are a spread of Ta–O bond distances ranging from 1.94–2.05 Å. In the second Ta site, Ta is bonded to six O atoms to form TaO6 octahedra that share corners with six TaO6 octahedra and an edgeedge with one TaO7 pentagonal bipyramid. The corner-sharing octahedra tilt angles range from 3–46°. There are a spread of Ta–O bond distances ranging from 1.94–2.09 Å. In the third Ta site, Ta is bonded to six O atoms to form TaO6 octahedra that share corners with six TaO6 octahedra and an edgeedge with one TaO7 pentagonal bipyramid. The corner-sharing octahedra tilt angles range from 17–40°. There are a spread of Ta–O bond distances ranging from 1.88–2.18 Å. In the fourth Ta site, Ta is bonded to six O atoms to form TaO6 octahedra that share corners with six TaO6 octahedra and an edgeedge with one TaO7 pentagonal bipyramid. The corner-sharing octahedra tilt angles range from 5–38°. There are a spread of Ta–O bond distances ranging from 1.91–2.09 Å. In the fifth Ta site, Ta is bonded to six O atoms to form TaO6 octahedra that share corners with six TaO6 octahedra and an edgeedge with one TaO7 pentagonal bipyramid. The corner-sharing octahedra tilt angles range from 8–36°. There are a spread of Ta–O bond distances ranging from 1.91–2.12 Å. In the sixth Ta site, Ta is bonded to seven O atoms to form TaO7 pentagonal bipyramids that share corners with two equivalent TaO7 pentagonal bipyramids and edges with five TaO6 octahedra. There are a spread of Ta–O bond distances ranging from 1.96–2.13 Å. In the seventh Ta site, Ta is bonded to six O atoms to form corner-sharing TaO6 octahedra. The corner-sharing octahedra tilt angles range from 13–46°. There are a spread of Ta–O bond distances ranging from 1.93–2.04 Å. There are nineteen inequivalent O sites. In the first O site, O is bonded in a linear geometry to one Na and two equivalent Ta atoms. In the second O site, O is bonded in a linear geometry to two equivalent Ta atoms. In the third O site, O is bonded in a distorted T-shaped geometry to one Na and two equivalent Ta atoms. In the fourth O site, O is bonded in a linear geometry to two equivalent Ta atoms. In the fifth O site, O is bonded in a linear geometry to two equivalent Ta atoms. In the sixth O site, O is bonded in a linear geometry to two equivalent Ta atoms. In the seventh O site, O is bonded in a distorted T-shaped geometry to one Na and two equivalent Ta atoms. In the eighth O site, O is bonded to two equivalent Na and two Ta atoms to form distorted corner-sharing ONa2Ta2 trigonal pyramids. In the ninth O site, O is bonded in a distorted trigonal non-coplanar geometry to three Ta atoms. In the tenth O site, O is bonded in a distorted trigonal non-coplanar geometry to three Ta atoms. In the eleventh O site, O is bonded in a distorted trigonal non-coplanar geometry to three Ta atoms. In the twelfth O site, O is bonded in a distorted trigonal planar geometry to three Ta atoms. In the thirteenth O site, O is bonded in a distorted trigonal planar geometry to three Ta atoms. In the fourteenth O site, O is bonded in a bent 150 degrees geometry to two Ta atoms. In the fifteenth O site, O is bonded in a distorted rectangular see-saw-like geometry to two equivalent Na and two Ta atoms. In the sixteenth O site, O is bonded in a distorted bent 150 degrees geometry to two equivalent Na and two Ta atoms. In the seventeenth O site, O is bonded in a bent 150 degrees geometry to two Ta atoms. In the eighteenth O site, O is bonded in a bent 150 degrees geometry to two Ta atoms. In the nineteenth O site, O is bonded in a bent 150 degrees geometry to two Ta atoms.