What Is the Origin of Born Repulsion in Atoms?

[smimth]

hello,

I am curious about born repulsion of atoms, ie short range repulsion energy term proportional to 1/r^n. I find this in many solid state type books and they all call it the born repulsion and give no hints to its derivation or where it comes from. In _Atomic Physics_ 6th ed. by Max Born, I find "a law of the form b/r^n has been tried with good success..." in chap. IX but gives no hints to the origin of this form. Is anyone aware of a reference where the theory behind this form is described? Perhaps it is even in _Atomic Physics_ but my browsing has not found it yet.

Thank you,
smimth

 

[genneth]

There is no theory --- it is purely a functional form for a short-range repulsion that is convenient. It turns out that usually the exact form of the interaction does not matter, so one just picks something which makes the algebra simpler.