Isoresonant benzenoids

A test is made of the concept of "isoresonance", wherein two species are so related if each have like numbers of the same (type of) bonds and there is a suitable isomorphism between superpositions of pairs of Kekule structure s. The test is primarily via computations using a few different semiempiric al quantum-chemical models on 48 benzenoid structures with over 30 (sometim es overlapping) different isoresonant pairs. Some lest is made comparing ot her experimental data. There is observed to be a high correlation between r esonance energies (or certain other properties) of isoresonant pairs-indeed more so than correspondences predicted by some other previously proposed c lassifications.