A simple theory of the interaction potential between heavy ions V, based on the local density approach and the frozen density model, is applied to a number of pairs of nuclei with neutron excess. The energy density needed for calculating V is expressed in a simple way through the equilibrium properties of nuclear matter, a phenomenological density gradient term, and nucleon density distributions in the two colliding nuclei. The Coulomb barrier in the calculated potential compares favorably with other estimates.

PACS numbers: 25.70.--z