On the HOMA index of some acyclic and conducting systems

The geometrical aromaticity HOMA index can be useful for acyclic linear systems. It approaches a horizontal asymptote as the periodic linear system increases in size. For the unsaturated polymers such as polyenes or polythiophenes, the index seems to be a fair measure of the p-electron delocalization and thus to be a good simple tool for the design of conducting polymers.