HgCd3 is beta Cu3Ti-like structured and crystallizes in the hexagonal P6_3/mmc space group. Hg(1) is bonded to twelve equivalent Cd(1) atoms to form HgCd12 cuboctahedra that share corners with six equivalent Hg(1)Cd12 cuboctahedra, corners with twelve equivalent Cd(1)Cd8Hg4 cuboctahedra, edges with eighteen equivalent Cd(1)Cd8Hg4 cuboctahedra, faces with eight equivalent Hg(1)Cd12 cuboctahedra, and faces with twelve equivalent Cd(1)Cd8Hg4 cuboctahedra. Cd(1) is bonded to four equivalent Hg(1) and eight equivalent Cd(1) atoms to form CdCd8Hg4 cuboctahedra that share corners with four equivalent Hg(1)Cd12 cuboctahedra, corners with fourteen equivalent Cd(1)Cd8Hg4 cuboctahedra, edges with six equivalent Hg(1)Cd12 cuboctahedra, edges with twelve equivalent Cd(1)Cd8Hg4 cuboctahedra, faces with four equivalent Hg(1)Cd12 cuboctahedra, and faces with sixteen equivalent Cd(1)Cd8Hg4 cuboctahedra.
HgCd3 is beta Cu3Ti-like structured and crystallizes in the hexagonal P6_3/mmc space group. Hg(1) is bonded to twelve equivalent Cd(1) atoms to form HgCd12 cuboctahedra that share corners with six equivalent Hg(1)Cd12 cuboctahedra, corners with twelve equivalent Cd(1)Cd8Hg4 cuboctahedra, edges with eighteen equivalent Cd(1)Cd8Hg4 cuboctahedra, faces with eight equivalent Hg(1)Cd12 cuboctahedra, and faces with twelve equivalent Cd(1)Cd8Hg4 cuboctahedra. There are six shorter (3.14 Å) and six longer (3.17 Å) Hg(1)-Cd(1) bond lengths. Cd(1) is bonded to four equivalent Hg(1) and eight equivalent Cd(1) atoms to form CdCd8Hg4 cuboctahedra that share corners with four equivalent Hg(1)Cd12 cuboctahedra, corners with fourteen equivalent Cd(1)Cd8Hg4 cuboctahedra, edges with six equivalent Hg(1)Cd12 cuboctahedra, edges with twelve equivalent Cd(1)Cd8Hg4 cuboctahedra, faces with four equivalent Hg(1)Cd12 cuboctahedra, and faces with sixteen equivalent Cd(1)Cd8Hg4 cuboctahedra. There are a spread of Cd(1)-Cd(1) bond distances ranging from 3.13-3.17 Å.