In electron density functions, maximal sets will generally represent bonds and atoms. One would like the criticality graph to approximate the structure of a molecule. Thus we may be required to modify the criticality graph so that we make parentage relations based on the physically closest descendant. The original definition makes the relation defined by value closeness. However, this may suffice as an electron density function represents a potential field subject to the inverse square law, and thus it is possible that value closeness will be equivalent to physical closeness. We will perform experiments to determine the correct approach.