Pu2Se3 is Stibnite structured and crystallizes in the orthorhombic Pnma space group. There are two inequivalent Pu sites. In the first Pu site, Pu(1) is bonded to two equivalent Se(1), two equivalent Se(3), and three equivalent Se(2) atoms to form a mixture of distorted corner and edge-sharing PuSe7 pentagonal bipyramids. In the second Pu site, Pu(2) is bonded in a 8-coordinate geometry to two equivalent Se(2), three equivalent Se(1), and three equivalent Se(3) atoms. There are three inequivalent Se sites. In the first Se site, Se(1) is bonded to two equivalent Pu(1) and three equivalent Pu(2) atoms to form a mixture of corner and edge-sharing SePu5 trigonal bipyramids. In the second Se site, Se(2) is bonded to two equivalent Pu(2) and three equivalent Pu(1) atoms to form a mixture of corner and edge-sharing SePu5 square pyramids. In the third Se site, Se(3) is bonded in a 5-coordinate geometry to two equivalent Pu(1) and three equivalent Pu(2) atoms.
Pu2Se3 is Stibnite structured and crystallizes in the orthorhombic Pnma space group. There are two inequivalent Pu sites. In the first Pu site, Pu(1) is bonded to two equivalent Se(1), two equivalent Se(3), and three equivalent Se(2) atoms to form a mixture of distorted corner and edge-sharing PuSe7 pentagonal bipyramids. Both Pu(1)-Se(1) bond lengths are 2.96 Å. There is one shorter (2.96 Å) and one longer (2.99 Å) Pu(1)-Se(3) bond length. There are two shorter (2.92 Å) and one longer (2.97 Å) Pu(1)-Se(2) bond length. In the second Pu site, Pu(2) is bonded in a 8-coordinate geometry to two equivalent Se(2), three equivalent Se(1), and three equivalent Se(3) atoms. Both Pu(2)-Se(2) bond lengths are 3.05 Å. There are two shorter (3.00 Å) and one longer (3.02 Å) Pu(2)-Se(1) bond length. There are two shorter (2.99 Å) and one longer (3.60 Å) Pu(2)-Se(3) bond length. There are three inequivalent Se sites. In the first Se site, Se(1) is bonded to two equivalent Pu(1) and three equivalent Pu(2) atoms to form a mixture of corner and edge-sharing SePu5 trigonal bipyramids. In the second Se site, Se(2) is bonded to two equivalent Pu(2) and three equivalent Pu(1) atoms to form a mixture of corner and edge-sharing SePu5 square pyramids. In the third Se site, Se(3) is bonded in a 5-coordinate geometry to two equivalent Pu(1) and three equivalent Pu(2) atoms.