Materials Data on NpSb3 by Materials Project

Abstract

NpSb3 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Np3+ is bonded to twelve Sb1- atoms to form NpSb12 cuboctahedra that share corners with four equivalent NpSb12 cuboctahedra, corners with sixteen equivalent SbNp4Sb4 cuboctahedra, edges with eight equivalent NpSb12 cuboctahedra, edges with eight equivalent SbNp4Sb4 cuboctahedra, and faces with four equivalent NpSb12 cuboctahedra. There are four shorter (3.15 Å) and eight longer (3.44 Å) Np–Sb bond lengths. There are two inequivalent Sb1- sites. In the first Sb1- site, Sb1- is bonded to four equivalent Np3+ and four equivalent Sb1- atoms to form distorted SbNp4Sb4 cuboctahedra that share corners with eight equivalent NpSb12 cuboctahedra, corners with sixteen equivalent SbNp4Sb4 cuboctahedra, edges with four equivalent NpSb12 cuboctahedra, edges with six equivalent SbNp4Sb4 cuboctahedra, and faces with four equivalent SbNp4Sb4 cuboctahedra. All Sb–Sb bond lengths are 3.15 Å. In the second Sb1- site, Sb1- is bonded in a square co-planar geometry to four equivalent Np3+ atoms.