材料期刊网

Starting from the extensional model Huckel Hamiltonian containing the next-neighbor hopping interactions, the energy band structure and their variation have been studied for polydiacetylenes (PDA's). With the increase of the next-neighbor hopping interaction parameter rho the results show that: (1) the electronic state symmetry is broken, (2) the locations and the widths of energy bands have been changed, and (3) the energy gap becomes narrower and the total bandwidth broader. Finally, the effect of the next-neighbor hopping interactions on the band-structure is discussed.