Adoption of Central Field Model at Equilibrium

Adoption of Central Field Model at Equilibrium.—To make progress, we now adopt the central field model, for which, for neutral molecules, we saw that the chemical potential n was zero. Secondly, we established the existence of an equilibrium bond length at Re, given by equation (89), where the virial theorem for equilibrium under purely Coulomb forces takes the usual form 

This simple relation will be confronted with the results of accurate self-consistent calculations for a variety of small molecules in the next section, where we shall see that, in spite of its derivation from the central field model above, it is valid in a much wider context, to a useful approximation. 

---