A cluster compound containing both carbon (C) and boron (B) atoms as well as hydrogen (H) atoms external to the framework of the cluster. A cluster compound is one with insufficient electrons to allow for classical two-center two-electron bonds between all adjacent atoms. Sometimes the term carborane is used as a synonym for closo-1,2-C₂B₁₀H₁₂, commonly referred to as ortho-carborane. Carboranes are of interest because of their nonclassical bonding, their relatively high thermal stability, and their ability, when containing the ¹⁰B isotope, to capture neutrons efficiently.