Metalization structures are modeled by employing automatic substrate grounding and shielding generation in conjunction with a design and simulation process for modeling the charge distributions and the interactions of these charge distributions on metalization structures arising from voltages and currents flowing in metalization structures. By generating and, then, employing a grounding structure that is optimized to strongly screen the metalization structure being designed and simulated, the requirement is eliminated for the accurate incorporation of the strongly dependent long range metalization sub unit to sub unit charge distribution coupling from the charge distribution determination process. In one embodiment of the invention, representative metalization sub units are selected, such as straight sections of infinitesimal length, right angle bends and intersections. Charge distributions are determined in those representative sub units based on the assumption that the integrated circuit substrate strongly suppresses any long range circuit interactions or frequency dependent effects. Then, based on the above assumption, self and mutual interactions are determined of the metalization sub units. Further, based on determined characteristics of those sub units, substrate grounding structures are determined and constructed that ensure the validity of the simulation assumption that the substrate grounding is adequate to strongly suppress any long range circuit interactions and/or frequency dependent effects. The determined self and mutual interactions can then be used as initial solutions to describe all interactions between similar metalization sub units in the overall physical metalization structure to be fabricated.