The next higher rectilinear analog of pentalene and indacene (sections 3.1 and 3.2) is dicyclopenta[b, g]naphthalene, which has been synthesized. As with indacene, substitution at both the six-and five-membered rings induces the requisite bondlength delocalization, which induces the Hund's rule violation. Unlike in s-indacene, we do not find a substituted molecule where the gap between S 1 and T 1 is inverted.