DOI: 10.17188/1679292
title: Materials Data on Cs2U4Nb4O23 by Materials Project

description: Cs2U4Nb4O23 crystallizes in the monoclinic Cm space group. The structure is three-dimensional. there are two inequivalent Cs1+ sites. In the first Cs1+ site, Cs1+ is bonded in a body-centered cubic geometry to eight O2- atoms. There are a spread of Cs–O bond distances ranging from 3.29–3.32 Å. In the second Cs1+ site, Cs1+ is bonded in a body-centered cubic geometry to eight O2- atoms. There are a spread of Cs–O bond distances ranging from 3.23–3.29 Å. There are two inequivalent U6+ sites. In the first U6+ site, U6+ is bonded to seven O2- atoms to form distorted UO7 pentagonal bipyramids that share a cornercorner with one NbO6 octahedra, a cornercorner with one NbO5 trigonal bipyramid, an edgeedge with one NbO6 octahedra, edges with two equivalent UO7 pentagonal bipyramids, and an edgeedge with one NbO5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 38°. There are a spread of U–O bond distances ranging from 1.83–2.50 Å. In the second U6+ site, U6+ is bonded to seven O2- atoms to form distorted UO7 pentagonal bipyramids that share a cornercorner with one NbO6 octahedra, a cornercorner with one NbO5 trigonal bipyramid, an edgeedge with one NbO6 octahedra, edges with two equivalent UO7 pentagonal bipyramids, and an edgeedge with one NbO5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 38°. There are a spread of U–O bond distances ranging from 1.83–2.54 Å. There are two inequivalent Nb5+ sites. In the first Nb5+ site, Nb5+ is bonded to five O2- atoms to form NbO5 trigonal bipyramids that share corners with two equivalent NbO6 octahedra, corners with two UO7 pentagonal bipyramids, a cornercorner with one NbO5 trigonal bipyramid, and edges with two UO7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 30–32°. There are a spread of Nb–O bond distances ranging from 1.88–2.02 Å. In the second Nb5+ site, Nb5+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with two UO7 pentagonal bipyramids, corners with two equivalent NbO5 trigonal bipyramids, an edgeedge with one NbO6 octahedra, and edges with two UO7 pentagonal bipyramids. There are a spread of Nb–O bond distances ranging from 1.98–2.06 Å. There are thirteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to two Cs1+ and one U6+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to two Cs1+ and one U6+ atom. In the third O2- site, O2- is bonded in a 2-coordinate geometry to one U6+ and two Nb5+ atoms. In the fourth O2- site, O2- is bonded in a 3-coordinate geometry to one U6+ and two Nb5+ atoms. In the fifth O2- site, O2- is bonded in a linear geometry to two equivalent Nb5+ atoms. In the sixth O2- site, O2- is bonded in a water-like geometry to two equivalent Nb5+ atoms. In the seventh O2- site, O2- is bonded in a water-like geometry to two equivalent Nb5+ atoms. In the eighth O2- site, O2- is bonded in a 3-coordinate geometry to two U6+ and one Nb5+ atom. In the ninth O2- site, O2- is bonded in a 3-coordinate geometry to two U6+ and one Nb5+ atom. In the tenth O2- site, O2- is bonded in a 3-coordinate geometry to two U6+ and one Nb5+ atom. In the eleventh O2- site, O2- is bonded in a 3-coordinate geometry to two U6+ and one Nb5+ atom. In the twelfth O2- site, O2- is bonded in a single-bond geometry to two Cs1+ and one U6+ atom. In the thirteenth O2- site, O2- is bonded in a single-bond geometry to two Cs1+ and one U6+ atom.