Pt3Hg crystallizes in the orthorhombic Cmmm space group. There are two inequivalent Pt sites. In the first Pt site, Pt(1) is bonded to two equivalent Pt(1), eight equivalent Pt(2), and two equivalent Hg(1) atoms to form PtHg2Pt10 cuboctahedra that share corners with twelve equivalent Pt(1)Hg2Pt10 cuboctahedra, edges with four equivalent Pt(1)Hg2Pt10 cuboctahedra, edges with four equivalent Hg(1)Hg2Pt10 cuboctahedra, edges with sixteen equivalent Pt(2)Hg4Pt8 cuboctahedra, faces with two equivalent Pt(1)Hg2Pt10 cuboctahedra, faces with eight equivalent Pt(2)Hg4Pt8 cuboctahedra, and faces with eight equivalent Hg(1)Hg2Pt10 cuboctahedra. In the second Pt site, Pt(2) is bonded to four equivalent Pt(1), four equivalent Pt(2), and four equivalent Hg(1) atoms to form distorted PtHg4Pt8 cuboctahedra that share corners with twelve equivalent Pt(2)Hg4Pt8 cuboctahedra, edges with eight equivalent Pt(1)Hg2Pt10 cuboctahedra, edges with eight equivalent Pt(2)Hg4Pt8 cuboctahedra, edges with eight equivalent Hg(1)Hg2Pt10 cuboctahedra, faces with four equivalent Pt(1)Hg2Pt10 cuboctahedra, faces with four equivalent Hg(1)Hg2Pt10 cuboctahedra, and faces with ten equivalent Pt(2)Hg4Pt8 cuboctahedra. Hg(1) is bonded to two equivalent Pt(1), eight equivalent Pt(2), and two equivalent Hg(1) atoms to form distorted HgHg2Pt10 cuboctahedra that share corners with twelve equivalent Hg(1)Hg2Pt10 cuboctahedra, edges with four equivalent Pt(1)Hg2Pt10 cuboctahedra, edges with four equivalent Hg(1)Hg2Pt10 cuboctahedra, edges with sixteen equivalent Pt(2)Hg4Pt8 cuboctahedra, faces with two equivalent Hg(1)Hg2Pt10 cuboctahedra, faces with eight equivalent Pt(1)Hg2Pt10 cuboctahedra, and faces with eight equivalent Pt(2)Hg4Pt8 cuboctahedra.
Pt3Hg crystallizes in the orthorhombic Cmmm space group. There are two inequivalent Pt sites. In the first Pt site, Pt(1) is bonded to two equivalent Pt(1), eight equivalent Pt(2), and two equivalent Hg(1) atoms to form PtHg2Pt10 cuboctahedra that share corners with twelve equivalent Pt(1)Hg2Pt10 cuboctahedra, edges with four equivalent Pt(1)Hg2Pt10 cuboctahedra, edges with four equivalent Hg(1)Hg2Pt10 cuboctahedra, edges with sixteen equivalent Pt(2)Hg4Pt8 cuboctahedra, faces with two equivalent Pt(1)Hg2Pt10 cuboctahedra, faces with eight equivalent Pt(2)Hg4Pt8 cuboctahedra, and faces with eight equivalent Hg(1)Hg2Pt10 cuboctahedra. Both Pt(1)-Pt(1) bond lengths are 2.91 Å. All Pt(1)-Pt(2) bond lengths are 2.86 Å. Both Pt(1)-Hg(1) bond lengths are 2.91 Å. In the second Pt site, Pt(2) is bonded to four equivalent Pt(1), four equivalent Pt(2), and four equivalent Hg(1) atoms to form distorted PtHg4Pt8 cuboctahedra that share corners with twelve equivalent Pt(2)Hg4Pt8 cuboctahedra, edges with eight equivalent Pt(1)Hg2Pt10 cuboctahedra, edges with eight equivalent Pt(2)Hg4Pt8 cuboctahedra, edges with eight equivalent Hg(1)Hg2Pt10 cuboctahedra, faces with four equivalent Pt(1)Hg2Pt10 cuboctahedra, faces with four equivalent Hg(1)Hg2Pt10 cuboctahedra, and faces with ten equivalent Pt(2)Hg4Pt8 cuboctahedra. All Pt(2)-Pt(2) bond lengths are 2.91 Å. All Pt(2)-Hg(1) bond lengths are 2.86 Å. Hg(1) is bonded to two equivalent Pt(1), eight equivalent Pt(2), and two equivalent Hg(1) atoms to form distorted HgHg2Pt10 cuboctahedra that share corners with twelve equivalent Hg(1)Hg2Pt10 cuboctahedra, edges with four equivalent Pt(1)Hg2Pt10 cuboctahedra, edges with four equivalent Hg(1)Hg2Pt10 cuboctahedra, edges with sixteen equivalent Pt(2)Hg4Pt8 cuboctahedra, faces with two equivalent Hg(1)Hg2Pt10 cuboctahedra, faces with eight equivalent Pt(1)Hg2Pt10 cuboctahedra, and faces with eight equivalent Pt(2)Hg4Pt8 cuboctahedra. Both Hg(1)-Hg(1) bond lengths are 2.91 Å.