I have found the following formula for the repulsion potential due to the overlap of the electron clouds arising from Pauli's exclusion principle:
$$V = A\exp(-r/\phi)$$
where r is the distance between ions. In terms of energy:
$$E = A\exp(-r/\phi)/r$$
What would be the final force expression?
I am calculating Pauli's pseudoforce (it's not a real force because the repulsion arises from electromagnetic interactions) for Na, Ca and K ions. I need the values for parameters $A$ and $\phi$, which are commonly fitted to energy curves. Do you know of any tables which have these parameters?. If so, could you please give me the references?