THE ENERGY-BAND STRUCTURE OF POLYACENE WITH SOLITON EXCITATIONS

Starting from the extensional Su-Schrieffer-Heeger model taking into a ccount the effects of interchain coupling, we have studied the energy spectra and electronic states of soliton excitation in polyacene. The dimerized displacement u(0) is found to be similar to the case of tran s-polyacetylene, and equals to 0.04 Angstrom. The energy-band gap is 0 .38 eV, in agreement with the results derived by other authors. Two ne w bound electronic states have been found in the conduction band and i n the valence band, which is different from the one of trans-polyacety lene. There exists two degenerate soliton states in the center of ener gy gap. Furthermore, the distribution of charge density and spin densi ty have been discussed in detail.