DOI: 10.17188/1676449
title: Materials Data on Na5U5O18 by Materials Project

description: Na5U5O18 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are five inequivalent Na sites. In the first Na site, Na is bonded in a 8-coordinate geometry to eight O atoms. There are a spread of Na–O bond distances ranging from 2.41–2.94 Å. In the second Na site, Na is bonded in a 8-coordinate geometry to eight O atoms. There are a spread of Na–O bond distances ranging from 2.41–2.94 Å. In the third Na site, Na is bonded in a 7-coordinate geometry to seven O atoms. There are a spread of Na–O bond distances ranging from 2.45–2.88 Å. In the fourth Na site, Na is bonded in a 7-coordinate geometry to seven O atoms. There are a spread of Na–O bond distances ranging from 2.44–2.84 Å. In the fifth Na site, Na is bonded in a 7-coordinate geometry to seven O atoms. There are a spread of Na–O bond distances ranging from 2.36–2.89 Å. There are five inequivalent U sites. In the first U site, U is bonded in a 7-coordinate geometry to seven O atoms. There are a spread of U–O bond distances ranging from 1.88–2.62 Å. In the second U site, U is bonded to seven O atoms to form distorted UO7 pentagonal bipyramids that share corners with two UO6 octahedra, an edgeedge with one UO6 octahedra, and an edgeedge with one UO7 pentagonal bipyramid. The corner-sharing octahedra tilt angles range from 48–49°. There are a spread of U–O bond distances ranging from 1.88–2.57 Å. In the third U site, U is bonded to seven O atoms to form distorted UO7 pentagonal bipyramids that share corners with two UO6 octahedra, edges with two UO6 octahedra, and an edgeedge with one UO7 pentagonal bipyramid. The corner-sharing octahedra tilt angles range from 32–34°. There are a spread of U–O bond distances ranging from 1.88–2.48 Å. In the fourth U site, U is bonded to six O atoms to form UO6 octahedra that share a cornercorner with one UO6 octahedra, corners with two UO7 pentagonal bipyramids, and edges with two UO7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 39°. There are a spread of U–O bond distances ranging from 1.90–2.20 Å. In the fifth U site, U is bonded to six O atoms to form UO6 octahedra that share a cornercorner with one UO6 octahedra, corners with two UO7 pentagonal bipyramids, and an edgeedge with one UO7 pentagonal bipyramid. The corner-sharing octahedral tilt angles are 39°. There are a spread of U–O bond distances ranging from 1.90–2.21 Å. There are eighteen inequivalent O sites. In the first O site, O is bonded to three Na and one U atom to form distorted ONa3U tetrahedra that share corners with two ONa3U tetrahedra, corners with four ONaU3 trigonal pyramids, an edgeedge with one ONa3U tetrahedra, and an edgeedge with one ONaU3 trigonal pyramid. In the second O site, O is bonded in a 4-coordinate geometry to three Na and one U atom. In the third O site, O is bonded in a 4-coordinate geometry to one Na and three U atoms. In the fourth O site, O is bonded to one Na and three U atoms to form distorted ONaU3 trigonal pyramids that share corners with two equivalent ONa3U tetrahedra, corners with three ONaU3 trigonal pyramids, an edgeedge with one ONa3U tetrahedra, and an edgeedge with one ONaU3 trigonal pyramid. In the fifth O site, O is bonded in a linear geometry to two U atoms. In the sixth O site, O is bonded to one Na and three U atoms to form distorted ONaU3 trigonal pyramids that share corners with three ONa3U tetrahedra, corners with four ONaU3 trigonal pyramids, an edgeedge with one ONa3U tetrahedra, and an edgeedge with one ONaU3 trigonal pyramid. In the seventh O site, O is bonded to one Na and three U atoms to form distorted ONaU3 trigonal pyramids that share corners with two ONa3U tetrahedra, corners with two ONaU3 trigonal pyramids, an edgeedge with one ONa3U tetrahedra, and edges with two ONaU3 trigonal pyramids. In the eighth O site, O is bonded in a 4-coordinate geometry to three Na and one U atom. In the ninth O site, O is bonded in a 4-coordinate geometry to three Na and one U atom. In the tenth O site, O is bonded in a 4-coordinate geometry to one Na and three U atoms. In the eleventh O site, O is bonded to one Na and three U atoms to form distorted ONaU3 trigonal pyramids that share corners with three ONa3U tetrahedra, corners with three ONaU3 trigonal pyramids, and an edgeedge with one ONa3U tetrahedra. In the twelfth O site, O is bonded in a 4-coordinate geometry to three Na and one U atom. In the thirteenth O site, O is bonded in a 4-coordinate geometry to three Na and one U atom. In the fourteenth O site, O is bonded in a 4-coordinate geometry to one Na and three U atoms. In the fifteenth O site, O is bonded to three Na and one U atom to form distorted ONa3U tetrahedra that share corners with two ONa3U tetrahedra, corners with two ONaU3 trigonal pyramids, and an edgeedge with one ONa3U tetrahedra. In the sixteenth O site, O is bonded to three Na and one U atom to form distorted ONa3U tetrahedra that share corners with three ONa3U tetrahedra, corners with two ONaU3 trigonal pyramids, edges with two ONa3U tetrahedra, and an edgeedge with one ONaU3 trigonal pyramid. In the seventeenth O site, O is bonded in a 4-coordinate geometry to three Na and one U atom. In the eighteenth O site, O is bonded to three Na and one U atom to form distorted ONa3U tetrahedra that share a cornercorner with one ONa3U tetrahedra, corners with two ONaU3 trigonal pyramids, edges with two ONa3U tetrahedra, and edges with two ONaU3 trigonal pyramids.