Tb2Mo3Si4 is delta Molybdenum Boride-derived structured and crystallizes in the monoclinic P2_1/c space group. Tb(1) is bonded in a 7-coordinate geometry to three equivalent Si(2) and four equivalent Si(1) atoms. There are two inequivalent Mo sites. In the first Mo site, Mo(1) is bonded to two equivalent Si(1) and four equivalent Si(2) atoms to form distorted corner-sharing MoSi6 octahedra. The corner-sharing octahedral tilt angles are 51°. 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 four equivalent Tb(1), one 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 three equivalent Tb(1), two equivalent Mo(1), three equivalent Mo(2), and one Si(2) atom.
Tb2Mo3Si4 is delta Molybdenum Boride-derived structured and crystallizes in the monoclinic P2_1/c space group. Tb(1) is bonded in a 7-coordinate geometry to three equivalent Si(2) and four equivalent Si(1) atoms. There are a spread of Tb(1)-Si(2) bond distances ranging from 2.83-2.87 Å. There are a spread of Tb(1)-Si(1) bond distances ranging from 2.81-3.05 Å. There are two inequivalent Mo sites. In the first Mo site, Mo(1) is bonded to two equivalent Si(1) and four equivalent Si(2) atoms to form distorted corner-sharing MoSi6 octahedra. The corner-sharing octahedral tilt angles are 51°. Both Mo(1)-Si(1) bond lengths are 2.67 Å. There are two shorter (2.66 Å) and two longer (2.70 Å) Mo(1)-Si(2) 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 are two shorter (2.56 Å) and one longer (2.64 Å) Mo(2)-Si(1) bond length. There are a spread of Mo(2)-Si(2) bond distances ranging from 2.53-2.63 Å. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to four equivalent Tb(1), one Mo(1), three equivalent Mo(2), and one Si(1) atom. The Si(1)-Si(1) bond length is 2.54 Å. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to three equivalent Tb(1), two equivalent Mo(1), three equivalent Mo(2), and one Si(2) atom. The Si(2)-Si(2) bond length is 2.52 Å.