UPt2Si2 crystallizes in the tetragonal P4/nmm space group. U(1) is bonded in a 16-coordinate geometry to four equivalent Pt(1), four equivalent Pt(2), four equivalent Si(1), and four equivalent Si(2) atoms. There are two inequivalent Pt sites. In the first Pt site, Pt(1) is bonded in a 5-coordinate geometry to four equivalent U(1), one Si(1), and four equivalent Si(2) atoms. In the second Pt site, Pt(2) is bonded to four equivalent U(1) and four equivalent Si(1) atoms to form distorted PtU4Si4 tetrahedra that share corners with twelve equivalent Si(2)U4Pt4 tetrahedra, edges with two equivalent Si(2)U4Pt4 tetrahedra, edges with four equivalent Pt(2)U4Si4 tetrahedra, and faces with four equivalent Pt(2)U4Si4 tetrahedra. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a 5-coordinate geometry to four equivalent U(1), one Pt(1), and four equivalent Pt(2) atoms. In the second Si site, Si(2) is bonded to four equivalent U(1) and four equivalent Pt(1) atoms to form distorted SiU4Pt4 tetrahedra that share corners with twelve equivalent Pt(2)U4Si4 tetrahedra, edges with two equivalent Pt(2)U4Si4 tetrahedra, edges with four equivalent Si(2)U4Pt4 tetrahedra, and faces with four equivalent Si(2)U4Pt4 tetrahedra.
UPt2Si2 crystallizes in the tetragonal P4/nmm space group. U(1) is bonded in a 16-coordinate geometry to four equivalent Pt(1), four equivalent Pt(2), four equivalent Si(1), and four equivalent Si(2) atoms. All U(1)-Pt(1) bond lengths are 3.21 Å. All U(1)-Pt(2) bond lengths are 3.26 Å. All U(1)-Si(1) bond lengths are 3.20 Å. All U(1)-Si(2) bond lengths are 3.21 Å. There are two inequivalent Pt sites. In the first Pt site, Pt(1) is bonded in a 5-coordinate geometry to four equivalent U(1), one Si(1), and four equivalent Si(2) atoms. The Pt(1)-Si(1) bond length is 2.40 Å. All Pt(1)-Si(2) bond lengths are 2.43 Å. In the second Pt site, Pt(2) is bonded to four equivalent U(1) and four equivalent Si(1) atoms to form distorted PtU4Si4 tetrahedra that share corners with twelve equivalent Si(2)U4Pt4 tetrahedra, edges with two equivalent Si(2)U4Pt4 tetrahedra, edges with four equivalent Pt(2)U4Si4 tetrahedra, and faces with four equivalent Pt(2)U4Si4 tetrahedra. All Pt(2)-Si(1) bond lengths are 2.47 Å. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a 5-coordinate geometry to four equivalent U(1), one Pt(1), and four equivalent Pt(2) atoms. In the second Si site, Si(2) is bonded to four equivalent U(1) and four equivalent Pt(1) atoms to form distorted SiU4Pt4 tetrahedra that share corners with twelve equivalent Pt(2)U4Si4 tetrahedra, edges with two equivalent Pt(2)U4Si4 tetrahedra, edges with four equivalent Si(2)U4Pt4 tetrahedra, and faces with four equivalent Si(2)U4Pt4 tetrahedra.