More generally, we have accounted for a large variety of metalloporphene band structures, and properties related to them, by applying the concepts of antiaromaticity and (Baird) aromaticity. Antiaromatic motifs in materials are desirable as they are often associated with low redox potentials, 53 open-shell character, 54 and high carrier mobility, 55 and this work is a step towards a deeper understanding of their electronic structure.