PbU2Se5 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent U sites. In the first U site, U(1) is bonded in a 8-coordinate geometry to two equivalent Se(1), two equivalent Se(3), two equivalent Se(4), and two equivalent Se(5) atoms. In the second U site, U(2) is bonded in a 7-coordinate geometry to one Se(3), one Se(4), one Se(5), two equivalent Se(1), and two equivalent Se(2) atoms. Pb(1) is bonded to one Se(3), one Se(4), two equivalent Se(2), and two equivalent Se(5) atoms to form distorted edge-sharing PbSe6 pentagonal pyramids. There are five inequivalent Se sites. In the first Se site, Se(1) is bonded in a distorted rectangular see-saw-like geometry to two equivalent U(1) and two equivalent U(2) atoms. In the second Se site, Se(2) is bonded to two equivalent U(2) and two equivalent Pb(1) atoms to form distorted SeU2Pb2 trigonal pyramids that share corners with two equivalent Se(2)U2Pb2 trigonal pyramids, corners with two equivalent Se(3)U3Pb trigonal pyramids,  an edgeedge with one Se(2)U2Pb2 trigonal pyramid, and  an edgeedge with one Se(3)U3Pb trigonal pyramid. In the third Se site, Se(3) is bonded to one U(2), two equivalent U(1), and one Pb(1) atom to form SeU3Pb trigonal pyramids that share corners with two equivalent Se(2)U2Pb2 trigonal pyramids, corners with two equivalent Se(3)U3Pb trigonal pyramids, and  an edgeedge with one Se(2)U2Pb2 trigonal pyramid. In the fourth Se site, Se(4) is bonded in a distorted see-saw-like geometry to one U(2), two equivalent U(1), and one Pb(1) atom. In the fifth Se site, Se(5) is bonded in a 3-coordinate geometry to one U(2), two equivalent U(1), and two equivalent Pb(1) atoms.
PbU2Se5 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent U sites. In the first U site, U(1) is bonded in a 8-coordinate geometry to two equivalent Se(1), two equivalent Se(3), two equivalent Se(4), and two equivalent Se(5) atoms. There is one shorter (2.98 Å) and one longer (3.02 Å) U(1)-Se(1) bond length. There is one shorter (2.93 Å) and one longer (3.21 Å) U(1)-Se(3) bond length. There is one shorter (2.92 Å) and one longer (2.93 Å) U(1)-Se(4) bond length. There is one shorter (2.90 Å) and one longer (3.05 Å) U(1)-Se(5) bond length. In the second U site, U(2) is bonded in a 7-coordinate geometry to one Se(3), one Se(4), one Se(5), two equivalent Se(1), and two equivalent Se(2) atoms. The U(2)-Se(3) bond length is 2.91 Å. The U(2)-Se(4) bond length is 3.00 Å. The U(2)-Se(5) bond length is 2.94 Å. There is one shorter (2.85 Å) and one longer (2.88 Å) U(2)-Se(1) bond length. There is one shorter (2.81 Å) and one longer (2.91 Å) U(2)-Se(2) bond length. Pb(1) is bonded to one Se(3), one Se(4), two equivalent Se(2), and two equivalent Se(5) atoms to form distorted edge-sharing PbSe6 pentagonal pyramids. The Pb(1)-Se(3) bond length is 2.95 Å. The Pb(1)-Se(4) bond length is 3.18 Å. There is one shorter (2.92 Å) and one longer (3.13 Å) Pb(1)-Se(2) bond length. There is one shorter (3.24 Å) and one longer (3.25 Å) Pb(1)-Se(5) bond length. There are five inequivalent Se sites. In the first Se site, Se(1) is bonded in a distorted rectangular see-saw-like geometry to two equivalent U(1) and two equivalent U(2) atoms. In the second Se site, Se(2) is bonded to two equivalent U(2) and two equivalent Pb(1) atoms to form distorted SeU2Pb2 trigonal pyramids that share corners with two equivalent Se(2)U2Pb2 trigonal pyramids, corners with two equivalent Se(3)U3Pb trigonal pyramids,  an edgeedge with one Se(2)U2Pb2 trigonal pyramid, and  an edgeedge with one Se(3)U3Pb trigonal pyramid. In the third Se site, Se(3) is bonded to one U(2), two equivalent U(1), and one Pb(1) atom to form SeU3Pb trigonal pyramids that share corners with two equivalent Se(2)U2Pb2 trigonal pyramids, corners with two equivalent Se(3)U3Pb trigonal pyramids, and  an edgeedge with one Se(2)U2Pb2 trigonal pyramid. In the fourth Se site, Se(4) is bonded in a distorted see-saw-like geometry to one U(2), two equivalent U(1), and one Pb(1) atom. In the fifth Se site, Se(5) is bonded in a 3-coordinate geometry to one U(2), two equivalent U(1), and two equivalent Pb(1) atoms.