These clusters consist of at least two different (semi)metallic elements, and possess more direct metal-metal than metal-ligand contacts. The suffix "oid" designate that such clusters possess at a molecular scale, atom arrangements that appear in bulk intermetallic compounds with high coordination numbers of the atoms, such as for example in Laves phase and Hume-Rothery phases. Ligand-free intermetalloid clusters include also endohedrally filled Zintl clusters. A synonym for ligand-stabilized intermetalloid clusters is "molecular alloy". The clusters appear as discrete units in intermetallic compounds separated from each other by electropositive atoms such as [Sn@Cu@Sn], as soluble ions [As@Ni@As] or as ligand-stabilized molecules such as [Mo(ZnCH)(ZnCp*)].