Variational study of the metal-insulator transition in polyacetylene

Summary form only given, as follows. The one-dimensional Peierls-Hubbard model is shown to describe in a natural way the metal-insulator transition observed in polyacetylene as a function of doping [l]. A single set of parameters is able to account for the insulating state at half-filling (dimerization, optical gap), charged solitons close to half filling and a transition to a state with vanishing gap at a doping concentration of about 8%. For higher doping the system is a strongly correlated metal, which is particularly sensitive to the effects of impurities and interchain coupling.