Scaling of the Platt electrostatic model of diatomic hydrides

The Platt electrostatic model of a diatomic hydride is modified by the introduction of a scale factor which depends on the internuclear distance. This has the theoretical advantage of enabling the molecular virial theorem to be satisfied and the practical advantage, as shown by some examples, of improving the agreement with experiment particularly for the lighter molecules. The calculation of the scale factor requires two more integrals but the equilibrium internuclear distance and the force constant can still be interpreted electrostatically.