HfPt4 crystallizes in the tetragonal P4/mmm space group. There are two inequivalent Hf sites. In the first Hf site, Hf(1) is bonded to four equivalent Pt(2), four equivalent Pt(4), and four equivalent Pt(5) atoms to form HfPt12 cuboctahedra that share corners with four equivalent Hf(1)Pt12 cuboctahedra, corners with four equivalent Hf(2)Pt12 cuboctahedra, corners with four equivalent Pt(7)Pt12 cuboctahedra, edges with four equivalent Pt(1)Pt12 cuboctahedra,  a faceface with one Hf(2)Pt12 cuboctahedra,  a faceface with one Pt(7)Pt12 cuboctahedra, and faces with four equivalent Hf(1)Pt12 cuboctahedra. In the second Hf site, Hf(2) is bonded to four equivalent Pt(3), four equivalent Pt(5), and four equivalent Pt(6) atoms to form a mixture of face and corner-sharing HfPt12 cuboctahedra. There are seven inequivalent Pt sites. In the first Pt site, Pt(1) is bonded to four equivalent Pt(7) and eight equivalent Pt(4) atoms to form PtPt12 cuboctahedra that share corners with four equivalent Pt(1)Pt12 cuboctahedra, edges with eight equivalent Hf(1)Pt12 cuboctahedra, faces with four equivalent Pt(1)Pt12 cuboctahedra, and faces with four equivalent Pt(7)Pt12 cuboctahedra. In the second Pt site, Pt(2) is bonded in a distorted rectangular see-saw-like geometry to four equivalent Hf(1) atoms. In the third Pt site, Pt(3) is bonded in a distorted rectangular see-saw-like geometry to four equivalent Hf(2) atoms. In the fourth Pt site, Pt(4) is bonded in a distorted L-shaped geometry to two equivalent Hf(1), two equivalent Pt(1), and two equivalent Pt(7) atoms. In the fifth Pt site, Pt(5) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Hf(1) and two equivalent Hf(2) atoms. In the sixth Pt site, Pt(6) is bonded in a distorted square co-planar geometry to four equivalent Hf(2) atoms. In the seventh Pt site, Pt(7) is bonded to four equivalent Pt(1) and eight equivalent Pt(4) atoms to form PtPt12 cuboctahedra that share corners with four equivalent Pt(7)Pt12 cuboctahedra, corners with eight equivalent Hf(1)Pt12 cuboctahedra, faces with two equivalent Hf(1)Pt12 cuboctahedra, faces with four equivalent Pt(1)Pt12 cuboctahedra, and faces with four equivalent Pt(7)Pt12 cuboctahedra.
HfPt4 crystallizes in the tetragonal P4/mmm space group. There are two inequivalent Hf sites. In the first Hf site, Hf(1) is bonded to four equivalent Pt(2), four equivalent Pt(4), and four equivalent Pt(5) atoms to form HfPt12 cuboctahedra that share corners with four equivalent Hf(1)Pt12 cuboctahedra, corners with four equivalent Hf(2)Pt12 cuboctahedra, corners with four equivalent Pt(7)Pt12 cuboctahedra, edges with four equivalent Pt(1)Pt12 cuboctahedra,  a faceface with one Hf(2)Pt12 cuboctahedra,  a faceface with one Pt(7)Pt12 cuboctahedra, and faces with four equivalent Hf(1)Pt12 cuboctahedra. All Hf(1)-Pt(2) bond lengths are 2.82 Å. All Hf(1)-Pt(4) bond lengths are 2.75 Å. All Hf(1)-Pt(5) bond lengths are 2.89 Å. In the second Hf site, Hf(2) is bonded to four equivalent Pt(3), four equivalent Pt(5), and four equivalent Pt(6) atoms to form a mixture of face and corner-sharing HfPt12 cuboctahedra. All Hf(2)-Pt(3) bond lengths are 2.82 Å. All Hf(2)-Pt(5) bond lengths are 2.81 Å. All Hf(2)-Pt(6) bond lengths are 2.84 Å. There are seven inequivalent Pt sites. In the first Pt site, Pt(1) is bonded to four equivalent Pt(7) and eight equivalent Pt(4) atoms to form PtPt12 cuboctahedra that share corners with four equivalent Pt(1)Pt12 cuboctahedra, edges with eight equivalent Hf(1)Pt12 cuboctahedra, faces with four equivalent Pt(1)Pt12 cuboctahedra, and faces with four equivalent Pt(7)Pt12 cuboctahedra. All Pt(1)-Pt(7) bond lengths are 2.82 Å. All Pt(1)-Pt(4) bond lengths are 2.84 Å. In the second Pt site, Pt(2) is bonded in a distorted rectangular see-saw-like geometry to four equivalent Hf(1) atoms. In the third Pt site, Pt(3) is bonded in a distorted rectangular see-saw-like geometry to four equivalent Hf(2) atoms. In the fourth Pt site, Pt(4) is bonded in a distorted L-shaped geometry to two equivalent Hf(1), two equivalent Pt(1), and two equivalent Pt(7) atoms. Both Pt(4)-Pt(7) bond lengths are 2.84 Å. In the fifth Pt site, Pt(5) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Hf(1) and two equivalent Hf(2) atoms. In the sixth Pt site, Pt(6) is bonded in a distorted square co-planar geometry to four equivalent Hf(2) atoms. In the seventh Pt site, Pt(7) is bonded to four equivalent Pt(1) and eight equivalent Pt(4) atoms to form PtPt12 cuboctahedra that share corners with four equivalent Pt(7)Pt12 cuboctahedra, corners with eight equivalent Hf(1)Pt12 cuboctahedra, faces with two equivalent Hf(1)Pt12 cuboctahedra, faces with four equivalent Pt(1)Pt12 cuboctahedra, and faces with four equivalent Pt(7)Pt12 cuboctahedra.