The periodicity of diatomic molecules

The possibility of molecular periodicity is discussed. A periodic table of diatomic molecules classified according to their electronic configuration is compiled. Many important properties including the dissociation energy, force constant, internuclear distance, electronic term symbols, transition frequency between states A and X, multiplicity, magnetic susceptibility as well as the frontier orbitals HOMO, LUMO exhibit periodic regularity throughout this table. A periodic law for diatomic molecules is thus proposed.