The electric attractions and repulsions of the ions on the surface of complex molecules play a critical role in many biochemical reactions. an interesting component of some of these processes is that chemical reactions or electron transfers result in a change of the shape of a molecule, exchanging chemical energy for electrical energy, and resulting in a different surface configuration and therefore different interactions. in this problem we will explore the effect of a change of configuration of a molecule on the force between it and an ion in a neighboring molecule.