Abstract: Two-dimentional electronic energy bands of iodine doped 1, 4-cis-polyisoprene(PI) are calculated by semiempirical EHMO/COmethod.The results show that the conductivity of iodine doped PIresults from the conduction of both directions parallel and perpendicular to the polymer chain; the conductivity of interchain is higher than that of intrachain.I₃^n-(n<1) anions are the dominant contributors to the conductivity in parallel to the chain direction, while both I₃^n- anions and double bonds of interchains play an important role in conductivity in the direction perpendicular to the chain.

Key words: 1,4-cis-polyisoprene, Two-dimentional electronic energy band, Dopant