Pu2Mo3Si4 crystallizes in the monoclinic P2_1/c space group. Pu(1) is bonded in a 7-coordinate geometry to three equivalent Si(1) and four equivalent Si(2) atoms. There are two inequivalent Mo sites. In the first Mo site, Mo(1) is bonded to two equivalent Si(2) and four equivalent Si(1) atoms to form distorted corner-sharing MoSi6 octahedra. The corner-sharing octahedral tilt angles are 50°. In the second Mo site, Mo(2) is bonded in a 6-coordinate geometry to three equivalent Si(1) and three equivalent Si(2) atoms. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to three equivalent Pu(1), two equivalent Mo(1), three equivalent Mo(2), and one Si(1) atom. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to four equivalent Pu(1), one Mo(1), three equivalent Mo(2), and one Si(2) atom.
Pu2Mo3Si4 crystallizes in the monoclinic P2_1/c space group. Pu(1) is bonded in a 7-coordinate geometry to three equivalent Si(1) and four equivalent Si(2) atoms. There are a spread of Pu(1)-Si(1) bond distances ranging from 2.84-2.88 Å. There are a spread of Pu(1)-Si(2) bond distances ranging from 2.76-2.91 Å. There are two inequivalent Mo sites. In the first Mo site, Mo(1) is bonded to two equivalent Si(2) and four equivalent Si(1) atoms to form distorted corner-sharing MoSi6 octahedra. The corner-sharing octahedral tilt angles are 50°. Both Mo(1)-Si(2) bond lengths are 2.65 Å. There are two shorter (2.64 Å) and two longer (2.66 Å) Mo(1)-Si(1) bond lengths. In the second Mo site, Mo(2) is bonded in a 6-coordinate geometry to three equivalent Si(1) and three equivalent Si(2) atoms. There is one shorter (2.55 Å) and two longer (2.58 Å) Mo(2)-Si(1) bond lengths. There is one shorter (2.53 Å) and two longer (2.57 Å) Mo(2)-Si(2) bond lengths. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to three equivalent Pu(1), two equivalent Mo(1), three equivalent Mo(2), and one Si(1) atom. The Si(1)-Si(1) bond length is 2.55 Å. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to four equivalent Pu(1), one Mo(1), three equivalent Mo(2), and one Si(2) atom. The Si(2)-Si(2) bond length is 2.49 Å.