Boron Hydrides
The stoichiometric name is followed by the number of hydrogen atoms in brackets. For example B2H6, diborane(6). More structural information can be conveyed by adding the "structural descriptor" closo-, nido-, arachno-, hypho-, klado- prefixes.
There is a fully systematic method of numbering the atoms in the boron hydride clusters, and a method of describing the position of bridging hydrogen atoms using the μ symbol.
Read more about this topic: IUPAC Nomenclature Of Inorganic Chemistry 2005