DOE OSTI2020
Ag3Cd crystallizes in the trigonal R-3m space group. The structure is three-dimensional. there are five inequivalent Ag sites. In the first Ag site, Ag is bonded to nine Ag and three equivalent Cd atoms to form AgCd3Ag9 cuboctahedra that share corners with twelve equivalent AgCd3Ag9 cuboctahedra, edges with six equivalent CdCd6Ag6 cuboctahedra, edges with eighteen AgCd3Ag9 cuboctahedra, faces with six equivalent CdCd6Ag6 cuboctahedra, and faces with twelve AgCd3Ag9 cuboctahedra. There are three shorter (2.93 Å) and six longer (3.01 Å) Ag–Ag bond lengths. All Ag–Cd bond lengths are 2.99 Å. In the second Ag site, Ag is bonded to twelve Ag atoms to form AgAg12 cuboctahedra that share corners with six equivalent AgAg12 cuboctahedra, corners with six equivalent CdCd6Ag6 cuboctahedra, edges with six equivalent CdCd6Ag6 cuboctahedra, edges with eighteen AgCd3Ag9 cuboctahedra, and faces with eighteen AgCd3Ag9 cuboctahedra. All Ag–Ag bond lengths are 3.01 Å. In the third Ag site, Ag is bonded to nine Ag and three equivalent Cd atoms to form AgCd3Ag9 cuboctahedra that share corners with seventeen AgCd3Ag9 cuboctahedra, edges with six equivalent CdCd6Ag6 cuboctahedra, edges with sixteen AgCd3Ag9 cuboctahedra, faces with six equivalent CdCd6Ag6 cuboctahedra, and faces with fifteen AgCd3Ag9 cuboctahedra. There are three shorter (2.93 Å) and six longer (3.01 Å) Ag–Ag bond lengths. All Ag–Cd bond lengths are 2.99 Å. In the fourth Ag site, Ag is bonded to sixteen Ag atoms to form AgAg16 cuboctahedra that share corners with six equivalent CdCd6Ag6 cuboctahedra, corners with sixteen AgCd3Ag9 cuboctahedra, edges with six equivalent CdCd6Ag6 cuboctahedra, edges with eighteen AgCd3Ag9 cuboctahedra, and faces with thirty-four AgCd3Ag9 cuboctahedra. There are a spread of Ag–Ag bond distances ranging from 2.93–6.02 Å. In the fifth Ag site, Ag is bonded to nine Ag and three equivalent Cd atoms to form AgCd3Ag9 cuboctahedra that share corners with seventeen AgCd3Ag9 cuboctahedra, edges with six equivalent CdCd6Ag6 cuboctahedra, edges with sixteen AgCd3Ag9 cuboctahedra, faces with six equivalent CdCd6Ag6 cuboctahedra, and faces with fifteen AgAg16 cuboctahedra. All Ag–Ag bond lengths are 3.01 Å. All Ag–Cd bond lengths are 2.99 Å. Cd is bonded to six equivalent Ag and six equivalent Cd atoms to form CdCd6Ag6 cuboctahedra that share corners with six equivalent AgAg12 cuboctahedra, corners with six equivalent CdCd6Ag6 cuboctahedra, edges with six equivalent CdCd6Ag6 cuboctahedra, edges with eighteen AgCd3Ag9 cuboctahedra, faces with six equivalent CdCd6Ag6 cuboctahedra, and faces with twelve equivalent AgCd3Ag9 cuboctahedra. All Cd–Cd bond lengths are 3.01 Å.