DOI: 10.17188/1656276
title: Materials Data on U2O5 by Materials Project

description: U2O5 crystallizes in the triclinic P1 space group. The structure is two-dimensional and consists of one U2O5 sheet oriented in the (0, 0, 1) direction. there are six inequivalent U5+ sites. In the first U5+ site, U5+ is bonded in a body-centered cubic geometry to eight O2- atoms. There are a spread of U–O bond distances ranging from 1.94–2.37 Å. In the second U5+ site, U5+ is bonded in a 4-coordinate geometry to ten O2- atoms. There are a spread of U–O bond distances ranging from 2.14–2.75 Å. In the third U5+ site, U5+ is bonded in a body-centered cubic geometry to eight O2- atoms. There are a spread of U–O bond distances ranging from 1.94–2.37 Å. In the fourth U5+ site, U5+ is bonded in a 4-coordinate geometry to seven O2- atoms. There are a spread of U–O bond distances ranging from 2.16–2.44 Å. In the fifth U5+ site, U5+ is bonded in a 11-coordinate geometry to eleven O2- atoms. There are a spread of U–O bond distances ranging from 2.24–2.65 Å. In the sixth U5+ site, U5+ is bonded in a 11-coordinate geometry to eleven O2- atoms. There are a spread of U–O bond distances ranging from 2.24–2.65 Å. There are fifteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a trigonal planar geometry to three equivalent U5+ atoms. In the second O2- site, O2- is bonded to four U5+ atoms to form a mixture of distorted corner and edge-sharing OU4 tetrahedra. In the third O2- site, O2- is bonded in a single-bond geometry to four U5+ atoms. In the fourth O2- site, O2- is bonded to four U5+ atoms to form a mixture of distorted corner and edge-sharing OU4 tetrahedra. In the fifth O2- site, O2- is bonded in a trigonal planar geometry to three equivalent U5+ atoms. In the sixth O2- site, O2- is bonded in a distorted single-bond geometry to one U5+ atom. In the seventh O2- site, O2- is bonded to four U5+ and three equivalent O2- atoms to form distorted OU4O3 trigonal pyramids that share corners with four OU4 tetrahedra, corners with three equivalent OU4O3 trigonal pyramids, edges with six equivalent OU4O3 trigonal pyramids, and faces with three equivalent OU4O3 trigonal pyramids. There are two shorter (2.45 Å) and one longer (2.47 Å) O–O bond lengths. In the eighth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to three equivalent U5+ atoms. In the ninth O2- site, O2- is bonded to four U5+ atoms to form OU4 tetrahedra that share corners with six equivalent OU4 tetrahedra and corners with four OU4O3 trigonal pyramids. In the tenth O2- site, O2- is bonded in a 4-coordinate geometry to four U5+ and one O2- atom. The O–O bond length is 2.52 Å. In the eleventh O2- site, O2- is bonded in a 1-coordinate geometry to four U5+ and one O2- atom. The O–O bond length is 2.51 Å. In the twelfth O2- site, O2- is bonded in a 6-coordinate geometry to six U5+ and eight O2- atoms. There are one shorter (2.45 Å) and two longer (2.46 Å) O–O bond lengths. In the thirteenth O2- site, O2- is bonded to four U5+ and three equivalent O2- atoms to form distorted OU4O3 trigonal pyramids that share corners with four OU4 tetrahedra, corners with three equivalent OU4O3 trigonal pyramids, edges with six equivalent OU4O3 trigonal pyramids, and faces with three equivalent OU4O3 trigonal pyramids. In the fourteenth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to three equivalent U5+ atoms. In the fifteenth O2- site, O2- is bonded to four U5+ atoms to form OU4 tetrahedra that share corners with six equivalent OU4 tetrahedra and corners with four OU4O3 trigonal pyramids.