Chemical space

Chemical space is the space spanned by all possible (i.e. energetically stable) stoichiometrical combinations of electrons and atomic nuclei and topologies (isomers) in molecules and also compounds in general. Chemical reactions allow us to move in chemical space. The mapping between chemical space and molecular properties is often not unique, meaning that there are usually more than one molecules which exhibit the same properties. Chemical space is being explored when carrying out material design or drug discovery.

It is assumed that the chemical space exceeds 1060 compounds and mankind will therefore never be able to create all those molecules. This becomes evident when knowing that only 27,000,000 molecules have been registered (and been made) so far.