Exotic atoms

Electrically charged elementary particles may be incorporated into atoms and molecules. A negatively charged particle may replace an electron while a positively charged particle may capture an electron forming an entity having many properties similar to those of an H atom. These unusual types of atom or molecule have many applications ranging from catalysing nuclear fusion, probing both the charge and nuclear matter distribution in a nucleus, providing accurate methods of measurement of fundamental constants and acting as tracing atoms for monitoring chemical reactions of atomic hydrogen.