Mo21S8 crystallizes in the tetragonal I4/m space group. There are six inequivalent Mo sites. In the first Mo site, Mo(1) is bonded in a 4-coordinate geometry to four equivalent S(1) atoms. In the second Mo site, Mo(2) is bonded in a 3-coordinate geometry to one S(1) and two equivalent S(2) atoms. In the third Mo site, Mo(3) is bonded in a 3-coordinate geometry to one S(1) and three equivalent S(2) atoms. In the fourth Mo site, Mo(4) is bonded in a 1-coordinate geometry to one S(2) atom. In the fifth Mo site, Mo(5) is bonded in a distorted L-shaped geometry to two equivalent S(2) atoms. In the sixth Mo site, Mo(6) is bonded in a square co-planar geometry to four equivalent S(1) atoms. There are two inequivalent S sites. In the first S site, S(1) is bonded in a 7-coordinate geometry to one Mo(2), one Mo(3), one Mo(6), and four equivalent Mo(1) atoms. In the second S site, S(2) is bonded in a 8-coordinate geometry to one Mo(4), two equivalent Mo(2), two equivalent Mo(5), and three equivalent Mo(3) atoms.
Mo21S8 crystallizes in the tetragonal I4/m space group. There are six inequivalent Mo sites. In the first Mo site, Mo(1) is bonded in a 4-coordinate geometry to four equivalent S(1) atoms. There are two shorter (2.52 Å) and two longer (2.53 Å) Mo(1)-S(1) bond lengths. In the second Mo site, Mo(2) is bonded in a 3-coordinate geometry to one S(1) and two equivalent S(2) atoms. The Mo(2)-S(1) bond length is 2.48 Å. Both Mo(2)-S(2) bond lengths are 2.44 Å. In the third Mo site, Mo(3) is bonded in a 3-coordinate geometry to one S(1) and three equivalent S(2) atoms. The Mo(3)-S(1) bond length is 2.41 Å. There are two shorter (2.38 Å) and one longer (2.83 Å) Mo(3)-S(2) bond length. In the fourth Mo site, Mo(4) is bonded in a 1-coordinate geometry to one S(2) atom. The Mo(4)-S(2) bond length is 2.63 Å. In the fifth Mo site, Mo(5) is bonded in a distorted L-shaped geometry to two equivalent S(2) atoms. Both Mo(5)-S(2) bond lengths are 2.41 Å. In the sixth Mo site, Mo(6) is bonded in a square co-planar geometry to four equivalent S(1) atoms. All Mo(6)-S(1) bond lengths are 2.44 Å. There are two inequivalent S sites. In the first S site, S(1) is bonded in a 7-coordinate geometry to one Mo(2), one Mo(3), one Mo(6), and four equivalent Mo(1) atoms. In the second S site, S(2) is bonded in a 8-coordinate geometry to one Mo(4), two equivalent Mo(2), two equivalent Mo(5), and three equivalent Mo(3) atoms.