The approach for constructing the qual. band structure of a polymer from the corresponding dimer was extended to the system with 2-fold screw axis or glide plane. The classification of energy levels of the dimer was dependent on pseudo-symmetry/antisymmetry instead of pseudo-in-phase/out-of-phase property of the orbitals. Several elec. conductive polymers were discussed including cis-polyacetylene, poly(p-phenylene) with a twist angle, and polypyrrole and its analogs. The nature of crystal orbitals at the top and bottom of valence and conductive bands were the most important for understanding the conductive behavior of polymers. These orbitals could be considered as the extension in polymers of the frontier orbitals in mols. The conclusions based on the anal. of these orbitals about the relaxation of the backbone of the polymers after doping were consistent with those based on the concepts of soliton, polaron, dipolaron, and so on.

Key words: DIMER, BAND STRUCTURES, MOLECULAR ORBITAL THEORY, CONFIGURATION, LONG CHAIN COMPOUND, ELECTRICAL CONDUCTIVITY, POLYACETYLENE, POLYPYRROLE, POLYARYLENE