1. An explosion in which the outward driving force is the electrical repulsion of charge.
2. A process in which a molecule moving with high velocity strikes a solid and the electrons that bond the molecule are torn off rapidly in violent collisions with the electrons of the solid; as a result, the molecule is suddenly transformed into a cluster of charged atomic constituents that then separate under the influence of their mutual Coulomb repulsion.

Coulomb explosions are most commonly studied using a particle accelerator, normally employed in nuclear physics research, to produce a beam of fast molecular ions that are directed onto a solid-foil target.