The Chemical Bond in H2: An Orbital Exchange Calculation

This paper extends the orbital exchange method calculation of H2 to include the possibility of a [HH, H+H-] resonance. The impact of the resonance on the orbitals overlaps and on the kinetic energy is described. The bond energy for H2 is found by varying the parameters associated with the compression (orbital reduction) and polarization of the 1s bonding orbitals of H and H-, and the extent of resonance, to obtain the maximum bond energy with the bonding overlap less than or equal to 1.0. The solution finds a binding energy, De, of 4.752 e.v. at a bond length of 0.733 with resonance fraction of 0.377. This is to be compared with the accepted value for De of 4.75 e.v. at 0.741. The success of this calculation strongly supports the hypothesis that overlapping bonding orbitals are not completely distinguishable and the efficacy of the orbital exchange method.