Hooray! In a publication in ACS Nano Letters, André Saraiva and Belita Koiller demonstrate how to identify a pair of impurities in silicon, in analogy to the H2 molecule. The peculiarities of the Si conduction electrons permit to electrically contact and pass a current through this molecule. The result — extremely different from Ohm’s law, makes possible to identify parameters of this molecule, such as the separation between impurities.