Materials Data on Nd2USe5 by Materials Project
UNd2Se5 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. U4+ is bonded to seven Se2- atoms to form distorted edge-sharing USe7 pentagonal bipyramids. There are a spread of U–Se bond distances ranging from 2.79–3.02 Å. Nd3+ is bonded in a 8-coordinate geometry to eight Se2- atoms. There are a spread of Nd–Se bond distances ranging from 3.04–3.20 Å. There are four inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to two equivalent U4+ and two equivalent Nd3+ atoms to form distorted SeNd2U2 trigonal pyramids that share corners with six SeNd4U square pyramids, corners with two equivalent SeNd4U trigonal bipyramids, corners with six equivalent SeNd2U2 trigonal pyramids, edges with three SeNd4U square pyramids, edges with two equivalent SeNd4U trigonal bipyramids, and an edgeedge with one SeNd2U2 trigonal pyramid. In the second Se2- site, Se2- is bonded to one U4+ and four equivalent Nd3+ atoms to form distorted SeNd4U trigonal bipyramids that share corners with six SeNd4U square pyramids, corners with four equivalent SeNd4U trigonal bipyramids, corners with four equivalent SeNd2U2 trigonal pyramids, edges with six SeNd4U square pyramids, and edges with four equivalent SeNd2U2 trigonal pyramids. In the third Se2- site, Se2- is bonded to one U4+ and four equivalent Nd3+ atoms to form SeNd4U square pyramids that share corners with four equivalent SeNd4U square pyramids, corners with five equivalent SeNd4U trigonal bipyramids, corners with eight equivalent SeNd2U2 trigonal pyramids, edges with three SeNd4U square pyramids, edges with two equivalent SeNd4U trigonal bipyramids, edges with two equivalent SeNd2U2 trigonal pyramids, and a faceface with one SeNd4U square pyramid. In the fourth Se2- site, Se2- is bonded to one U4+ and four equivalent Nd3+ atoms to form distorted SeNd4U square pyramids that share corners with eight SeNd4U square pyramids, a cornercorner with one SeNd4U trigonal bipyramid, corners with four equivalent SeNd2U2 trigonal pyramids, an edgeedge with one SeNd4U square pyramid, edges with four equivalent SeNd4U trigonal bipyramids, edges with four equivalent SeNd2U2 trigonal pyramids, and a faceface with one SeNd4U square pyramid.