U2PdSi3 is hexagonal omega structure-derived structured and crystallizes in the orthorhombic Pmm2 space group. There are two inequivalent U sites. In the first U site, U(1) is bonded to two equivalent Pd(1), two equivalent Si(3), four equivalent Si(1), and four equivalent Si(2) atoms to form USi10Pd2 cuboctahedra that share edges with four equivalent U(1)Si10Pd2 cuboctahedra, edges with eight equivalent U(2)Si8Pd4 cuboctahedra, faces with four equivalent U(1)Si10Pd2 cuboctahedra, and faces with four equivalent U(2)Si8Pd4 cuboctahedra. In the second U site, U(2) is bonded to four equivalent Pd(1), two equivalent Si(1), two equivalent Si(2), and four equivalent Si(3) atoms to form USi8Pd4 cuboctahedra that share edges with four equivalent U(2)Si8Pd4 cuboctahedra, edges with eight equivalent U(1)Si10Pd2 cuboctahedra, faces with four equivalent U(1)Si10Pd2 cuboctahedra, and faces with four equivalent U(2)Si8Pd4 cuboctahedra. Pd(1) is bonded in a 9-coordinate geometry to two equivalent U(1), four equivalent U(2), one Si(3), and two equivalent Si(2) atoms. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to two equivalent U(2), four equivalent U(1), one Si(2), and two equivalent Si(3) atoms. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to two equivalent U(2), four equivalent U(1), two equivalent Pd(1), and one Si(1) atom. In the third Si site, Si(3) is bonded in a 9-coordinate geometry to two equivalent U(1), four equivalent U(2), one Pd(1), and two equivalent Si(1) atoms.
U2PdSi3 is hexagonal omega structure-derived structured and crystallizes in the orthorhombic Pmm2 space group. There are two inequivalent U sites. In the first U site, U(1) is bonded to two equivalent Pd(1), two equivalent Si(3), four equivalent Si(1), and four equivalent Si(2) atoms to form USi10Pd2 cuboctahedra that share edges with four equivalent U(1)Si10Pd2 cuboctahedra, edges with eight equivalent U(2)Si8Pd4 cuboctahedra, faces with four equivalent U(1)Si10Pd2 cuboctahedra, and faces with four equivalent U(2)Si8Pd4 cuboctahedra. Both U(1)-Pd(1) bond lengths are 3.12 Å. Both U(1)-Si(3) bond lengths are 2.96 Å. All U(1)-Si(1) bond lengths are 3.02 Å. All U(1)-Si(2) bond lengths are 3.06 Å. In the second U site, U(2) is bonded to four equivalent Pd(1), two equivalent Si(1), two equivalent Si(2), and four equivalent Si(3) atoms to form USi8Pd4 cuboctahedra that share edges with four equivalent U(2)Si8Pd4 cuboctahedra, edges with eight equivalent U(1)Si10Pd2 cuboctahedra, faces with four equivalent U(1)Si10Pd2 cuboctahedra, and faces with four equivalent U(2)Si8Pd4 cuboctahedra. All U(2)-Pd(1) bond lengths are 3.08 Å. Both U(2)-Si(1) bond lengths are 2.98 Å. Both U(2)-Si(2) bond lengths are 3.17 Å. All U(2)-Si(3) bond lengths are 3.03 Å. Pd(1) is bonded in a 9-coordinate geometry to two equivalent U(1), four equivalent U(2), one Si(3), and two equivalent Si(2) atoms. The Pd(1)-Si(3) bond length is 2.42 Å. Both Pd(1)-Si(2) bond lengths are 2.42 Å. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to two equivalent U(2), four equivalent U(1), one Si(2), and two equivalent Si(3) atoms. The Si(1)-Si(2) bond length is 2.33 Å. Both Si(1)-Si(3) bond lengths are 2.36 Å. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to two equivalent U(2), four equivalent U(1), two equivalent Pd(1), and one Si(1) atom. In the third Si site, Si(3) is bonded in a 9-coordinate geometry to two equivalent U(1), four equivalent U(2), one Pd(1), and two equivalent Si(1) atoms.