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Mo3Si crystallizes in the cubic Pm-3n space group. The structure is three-dimensional. Mo is bonded in a 6-coordinate geometry to two equivalent Mo and four equivalent Si atoms. Both Mo–Mo bond lengths are 2.46 Å. All Mo–Si bond lengths are 2.75 Å. Si is bonded to twelve equivalent Mo atoms to form a mixture of edge and face-sharing SiMo12 cuboctahedra.
Mo5Si3 crystallizes in the tetragonal I4/mcm space group. The structure is three-dimensional. there are two inequivalent Mo+2.40+ sites. In the first Mo+2.40+ site, Mo+2.40+ is bonded to four equivalent Si4- atoms to form MoSi4 tetrahedra that share corners with sixteen equivalent MoSi6 pentagonal pyramids, edges with eight equivalent MoSi6 pentagonal pyramids, and edges with two equivalent MoSi4 tetrahedra. All Mo–Si bond lengths are 2.60 Å. In the second Mo+2.40+ site, Mo+2.40+ is bonded to six Si4- atoms to form distorted MoSi6 pentagonal pyramids that share corners with fifteen equivalent MoSi6 pentagonal pyramids, corners with four equivalent MoSi4 tetrahedra, edges with three equivalent MoSi6 pentagonal pyramids, edges with two equivalent MoSi4 tetrahedra, and faces with seven equivalent MoSi6 pentagonal pyramids. There are a spread of Mo–Si bond distances ranging from 2.54–2.82 Å. There are two inequivalent Si4- sites. In the first Si4- site, Si4- is bonded in a 10-coordinate geometry to ten Mo+2.40+ atoms. In the second Si4- site, Si4- is bonded in a 10-coordinate geometry to eight equivalent Mo+2.40+ and two equivalent Si4- atoms. Both Si–Si bond lengths are 2.47 Å.
MoSi2 is Titanium Disilicide-like structured and crystallizes in the hexagonal P6_222 space group. The structure is three-dimensional. Mo is bonded in a distorted q6 geometry to ten equivalent Si atoms. There are a spread of Mo–Si bond distances ranging from 2.58–2.69 Å. Si is bonded in a 10-coordinate geometry to five equivalent Mo and five equivalent Si atoms. There are a spread of Si–Si bond distances ranging from 2.57–2.69 Å.
MoSi is Tungsten Carbide structured and crystallizes in the hexagonal P-6m2 space group. The structure is three-dimensional. Mo4+ is bonded to six equivalent Si4- atoms to form a mixture of distorted corner, edge, and face-sharing MoSi6 pentagonal pyramids. All Mo–Si bond lengths are 2.52 Å. Si4- is bonded to six equivalent Mo4+ atoms to form a mixture of distorted corner, edge, and face-sharing SiMo6 pentagonal pyramids.
MoSi3 crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. Mo4+ is bonded to twelve equivalent Si+1.33- atoms to form a mixture of corner and face-sharing MoSi12 cuboctahedra. There are six shorter (2.61 Å) and six longer (2.81 Å) Mo–Si bond lengths. Si+1.33- is bonded in a 12-coordinate geometry to four equivalent Mo4+ and eight equivalent Si+1.33- atoms. There are a spread of Si–Si bond distances ranging from 2.48–2.89 Å.