Cs2U(PdSe2)3 crystallizes in the orthorhombic Fmmm space group. There are two inequivalent Cs sites. In the first Cs site, Cs(1) is bonded in a 8-coordinate geometry to four equivalent Se(1) and four equivalent Se(2) atoms. In the second Cs site, Cs(2) is bonded in a 10-coordinate geometry to two equivalent Se(1) and eight equivalent Se(2) atoms. U(1) is bonded in a 6-coordinate geometry to two equivalent Se(1) and four equivalent Se(2) atoms. There are two inequivalent Pd sites. In the first Pd site, Pd(1) is bonded in a square co-planar geometry to two equivalent Se(1) and two equivalent Se(2) atoms. In the second Pd site, Pd(2) is bonded in a square co-planar geometry to four equivalent Se(2) atoms. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded to one Cs(2), two equivalent Cs(1), one U(1), and two equivalent Pd(1) atoms to form a mixture of distorted edge, face, and corner-sharing SeCs3UPd2 octahedra. The corner-sharing octahedral tilt angles range from 8-81°. In the second Se site, Se(2) is bonded to one Cs(1), two equivalent Cs(2), one U(1), one Pd(1), and one Pd(2) atom to form a mixture of distorted edge, face, and corner-sharing SeCs3UPd2 octahedra. The corner-sharing octahedral tilt angles range from 8-101°.
Cs2U(PdSe2)3 crystallizes in the orthorhombic Fmmm space group. There are two inequivalent Cs sites. In the first Cs site, Cs(1) is bonded in a 8-coordinate geometry to four equivalent Se(1) and four equivalent Se(2) atoms. All Cs(1)-Se(1) bond lengths are 3.55 Å. All Cs(1)-Se(2) bond lengths are 3.55 Å. In the second Cs site, Cs(2) is bonded in a 10-coordinate geometry to two equivalent Se(1) and eight equivalent Se(2) atoms. Both Cs(2)-Se(1) bond lengths are 3.83 Å. There are four shorter (3.87 Å) and four longer (4.13 Å) Cs(2)-Se(2) bond lengths. U(1) is bonded in a 6-coordinate geometry to two equivalent Se(1) and four equivalent Se(2) atoms. Both U(1)-Se(1) bond lengths are 2.87 Å. All U(1)-Se(2) bond lengths are 2.85 Å. There are two inequivalent Pd sites. In the first Pd site, Pd(1) is bonded in a square co-planar geometry to two equivalent Se(1) and two equivalent Se(2) atoms. Both Pd(1)-Se(1) bond lengths are 2.48 Å. Both Pd(1)-Se(2) bond lengths are 2.49 Å. In the second Pd site, Pd(2) is bonded in a square co-planar geometry to four equivalent Se(2) atoms. All Pd(2)-Se(2) bond lengths are 2.47 Å. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded to one Cs(2), two equivalent Cs(1), one U(1), and two equivalent Pd(1) atoms to form a mixture of distorted edge, face, and corner-sharing SeCs3UPd2 octahedra. The corner-sharing octahedral tilt angles range from 8-81°. In the second Se site, Se(2) is bonded to one Cs(1), two equivalent Cs(2), one U(1), one Pd(1), and one Pd(2) atom to form a mixture of distorted edge, face, and corner-sharing SeCs3UPd2 octahedra. The corner-sharing octahedral tilt angles range from 8-101°.