text: A related class of octahedral clusters are of the type MXL where M is a metal usually of group 6 or group 7, X is a ligand and more specifically an inner ligand of the chalcohalide group such as chloride or sulfide and L is an "outer ligand."  The metal atoms define the vertices of an octahedron.  The overall point group symmetry is O.  Each face of the octahedron is capped with a chalcohalide and eight such atoms are at the corners of a cube. For this reason this geometry is called a face capped octahedral cluster.  Examples of  this type of clusters are the ReSCl anion.