Interatomic coulombic decay (ICD)

Has been experimentally confirmed. In 1997, this new mode of atomic decay was predicted for weakly bound atoms (as in a cluster or a fluid): One atom of the cluster is excited; but a different, neighboring atom ejects a low-energy electron. A research team in Germany has now unambiguously demonstrated ICD in the smallest possible cluster of neon atoms—a dimer—with the two atoms joined by the weak van der Waals force. The removal of a tightly bound electron from one of the atoms allowed a less tightly bound electron to jump into the vacancy and thereby gain energy. The extra energy was insufficient to liberate any of the remaining electrons in that same atom, but it was sufficient to release a low-energy electron from the neighboring atom. The scientists detected ICD’s fingerprint: the two neon ions, emitted back-to-back with equal momenta, and the ejected electron, with all kinetic energies adding...