Pt5SnSi crystallizes in the tetragonal P4/mmm space group. There are two inequivalent Pt sites. In the first Pt site, Pt(1) is bonded in a 2-coordinate geometry to two equivalent Pt(2), two equivalent Sn(1), and two equivalent Si(1) atoms. In the second Pt site, Pt(2) is bonded to eight equivalent Pt(1) and four equivalent Sn(1) atoms to form distorted PtSn4Pt8 cuboctahedra that share corners with four equivalent Pt(2)Sn4Pt8 cuboctahedra, faces with four equivalent Pt(2)Sn4Pt8 cuboctahedra, and faces with four equivalent Sn(1)Pt12 cuboctahedra. Sn(1) is bonded to four equivalent Pt(2) and eight equivalent Pt(1) atoms to form SnPt12 cuboctahedra that share corners with four equivalent Sn(1)Pt12 cuboctahedra, faces with four equivalent Pt(2)Sn4Pt8 cuboctahedra, and faces with four equivalent Sn(1)Pt12 cuboctahedra. Si(1) is bonded in a body-centered cubic geometry to eight equivalent Pt(1) atoms.
Pt5SnSi crystallizes in the tetragonal P4/mmm space group. There are two inequivalent Pt sites. In the first Pt site, Pt(1) is bonded in a 2-coordinate geometry to two equivalent Pt(2), two equivalent Sn(1), and two equivalent Si(1) atoms. Both Pt(1)-Pt(2) bond lengths are 2.88 Å. Both Pt(1)-Sn(1) bond lengths are 2.88 Å. Both Pt(1)-Si(1) bond lengths are 2.46 Å. In the second Pt site, Pt(2) is bonded to eight equivalent Pt(1) and four equivalent Sn(1) atoms to form distorted PtSn4Pt8 cuboctahedra that share corners with four equivalent Pt(2)Sn4Pt8 cuboctahedra, faces with four equivalent Pt(2)Sn4Pt8 cuboctahedra, and faces with four equivalent Sn(1)Pt12 cuboctahedra. All Pt(2)-Sn(1) bond lengths are 2.82 Å. Sn(1) is bonded to four equivalent Pt(2) and eight equivalent Pt(1) atoms to form SnPt12 cuboctahedra that share corners with four equivalent Sn(1)Pt12 cuboctahedra, faces with four equivalent Pt(2)Sn4Pt8 cuboctahedra, and faces with four equivalent Sn(1)Pt12 cuboctahedra. Si(1) is bonded in a body-centered cubic geometry to eight equivalent Pt(1) atoms.