Pd5TlSe crystallizes in the tetragonal P4/mmm space group. There are two inequivalent Pd sites. In the first Pd site, Pd(1) is bonded in a 4-coordinate geometry to two equivalent Pd(2), two equivalent Tl(1), and two equivalent Se(1) atoms. In the second Pd site, Pd(2) is bonded to eight equivalent Pd(1) and four equivalent Tl(1) atoms to form distorted PdTl4Pd8 cuboctahedra that share corners with four equivalent Pd(2)Tl4Pd8 cuboctahedra, faces with four equivalent Pd(2)Tl4Pd8 cuboctahedra, and faces with four equivalent Tl(1)Pd12 cuboctahedra. Tl(1) is bonded to four equivalent Pd(2) and eight equivalent Pd(1) atoms to form TlPd12 cuboctahedra that share corners with four equivalent Tl(1)Pd12 cuboctahedra, faces with four equivalent Pd(2)Tl4Pd8 cuboctahedra, and faces with four equivalent Tl(1)Pd12 cuboctahedra. Se(1) is bonded in a body-centered cubic geometry to eight equivalent Pd(1) atoms.
Pd5TlSe crystallizes in the tetragonal P4/mmm space group. There are two inequivalent Pd sites. In the first Pd site, Pd(1) is bonded in a 4-coordinate geometry to two equivalent Pd(2), two equivalent Tl(1), and two equivalent Se(1) atoms. Both Pd(1)-Pd(2) bond lengths are 2.87 Å. Both Pd(1)-Tl(1) bond lengths are 2.87 Å. Both Pd(1)-Se(1) bond lengths are 2.56 Å. In the second Pd site, Pd(2) is bonded to eight equivalent Pd(1) and four equivalent Tl(1) atoms to form distorted PdTl4Pd8 cuboctahedra that share corners with four equivalent Pd(2)Tl4Pd8 cuboctahedra, faces with four equivalent Pd(2)Tl4Pd8 cuboctahedra, and faces with four equivalent Tl(1)Pd12 cuboctahedra. All Pd(2)-Tl(1) bond lengths are 2.88 Å. Tl(1) is bonded to four equivalent Pd(2) and eight equivalent Pd(1) atoms to form TlPd12 cuboctahedra that share corners with four equivalent Tl(1)Pd12 cuboctahedra, faces with four equivalent Pd(2)Tl4Pd8 cuboctahedra, and faces with four equivalent Tl(1)Pd12 cuboctahedra. Se(1) is bonded in a body-centered cubic geometry to eight equivalent Pd(1) atoms.