On the forces acting between atoms and ions and the physical properties of matter in bulk

We consider a system, consisting of two atoms or ions, situated at a given distance, R from each other. Such a system is characterized by a certain potential energy F(R) , denoting the work required to decrease the interval between the two atoms or ions from oo to i? to R . The question of this potential energy has been the subject of numerous theoretical investigations, commencing with HEITLER’s and LONDON’s well-known papers (HEITLER and LONDON 1927; LONDON 1928 a , b ) on the reciprocal action of two atoms of hydrogen. On the other hand, we possess no further empirical knowledge concerning this potential energy F . The present paper is an attempt to analyse, by the aid of accessible experimental data, the question of the dependence of energy on the interatomic distance for atoms and ions with closed shells.