The wave function of H 2 represents a stronger covalent bond case with an admixture of the ionic part, absent in the single-electron of H + 2 . The three-electron wave function (Eq. ( )) reveals a more involved picture where distinguishing whether the chemical bond is covalent or ionic is not straightforward. It has a mixed resonant covalent-ionic bond character where two electrons always occupy one atom and the third is being transferred from one site to another. Such a process results in a more complex picture, in which the overall bond energy is reduced as shown in Tab. 1.