DOI: 10.17188/1750674
title: Materials Data on U2(SnPb)3 by Materials Project

description: U2(PbSn)3 crystallizes in the orthorhombic Pmmm space group. The structure is three-dimensional. U is bonded to six Pb and six Sn atoms to form USn6Pb6 cuboctahedra that share corners with twelve equivalent USn6Pb6 cuboctahedra, edges with twelve PbU4Sn6Pb2 cuboctahedra, edges with twelve SnU4Sn4Pb4 cuboctahedra, faces with six equivalent USn6Pb6 cuboctahedra, faces with six PbU4Sn6Pb2 cuboctahedra, and faces with six SnU4Sn4Pb4 cuboctahedra. There are four shorter (3.32 Å) and two longer (3.37 Å) U–Pb bond lengths. There are a spread of U–Sn bond distances ranging from 3.30–3.36 Å. There are two inequivalent Pb sites. In the first Pb site, Pb is bonded to four equivalent U, two equivalent Pb, and six Sn atoms to form distorted PbU4Sn6Pb2 cuboctahedra that share corners with twelve equivalent PbU4Sn6Pb2 cuboctahedra, edges with four equivalent PbU4Sn4Pb4 cuboctahedra, edges with eight equivalent USn6Pb6 cuboctahedra, edges with twelve SnU4Sn4Pb4 cuboctahedra, faces with four equivalent USn6Pb6 cuboctahedra, faces with six SnU4Sn4Pb4 cuboctahedra, and faces with eight PbU4Sn6Pb2 cuboctahedra. Both Pb–Pb bond lengths are 3.35 Å. There are a spread of Pb–Sn bond distances ranging from 3.31–3.36 Å. In the second Pb site, Pb is bonded to four equivalent U, four equivalent Pb, and four equivalent Sn atoms to form distorted PbU4Sn4Pb4 cuboctahedra that share corners with four equivalent PbU4Sn4Pb4 cuboctahedra, corners with eight equivalent SnU4Sn4Pb4 cuboctahedra, edges with eight equivalent USn6Pb6 cuboctahedra, edges with eight equivalent PbU4Sn6Pb2 cuboctahedra, edges with eight equivalent SnU4Sn4Pb4 cuboctahedra, faces with four equivalent USn6Pb6 cuboctahedra, faces with six SnU4Sn4Pb4 cuboctahedra, and faces with eight PbU4Sn6Pb2 cuboctahedra. All Pb–Sn bond lengths are 3.32 Å. There are three inequivalent Sn sites. In the first Sn site, Sn is bonded to four equivalent U, four equivalent Pb, and four equivalent Sn atoms to form distorted SnU4Sn4Pb4 cuboctahedra that share corners with four equivalent SnU4Sn4Pb4 cuboctahedra, corners with eight equivalent PbU4Sn4Pb4 cuboctahedra, edges with eight equivalent USn6Pb6 cuboctahedra, edges with eight equivalent PbU4Sn6Pb2 cuboctahedra, edges with eight equivalent SnU4Pb8 cuboctahedra, faces with four equivalent USn6Pb6 cuboctahedra, faces with six PbU4Sn6Pb2 cuboctahedra, and faces with eight SnU4Sn4Pb4 cuboctahedra. All Sn–Sn bond lengths are 3.32 Å. In the second Sn site, Sn is bonded to four equivalent U and eight Pb atoms to form SnU4Pb8 cuboctahedra that share corners with twelve SnU4Pb8 cuboctahedra, edges with eight equivalent USn6Pb6 cuboctahedra, edges with eight equivalent PbU4Sn6Pb2 cuboctahedra, edges with eight equivalent SnU4Sn4Pb4 cuboctahedra, faces with four equivalent USn6Pb6 cuboctahedra, faces with six SnU4Pb8 cuboctahedra, and faces with eight PbU4Sn6Pb2 cuboctahedra. In the third Sn site, Sn is bonded to four equivalent U, four equivalent Pb, and four equivalent Sn atoms to form distorted SnU4Sn4Pb4 cuboctahedra that share corners with twelve SnU4Pb8 cuboctahedra, edges with eight equivalent USn6Pb6 cuboctahedra, edges with sixteen PbU4Sn6Pb2 cuboctahedra, faces with four equivalent USn6Pb6 cuboctahedra, faces with four equivalent PbU4Sn6Pb2 cuboctahedra, and faces with ten SnU4Sn4Pb4 cuboctahedra.