ELECTRONIC AND LATTICE STRUCTURES IN POTASSIUM-DOPED STAGE-1 POLYACETYLENE

Interchain transfers (ICTs) via dopants and interchain Coulomb (ICC) a nd dopant Coulomb (DC) potentials in a Thomas-Fermi approximation are calculated in a stoichiometrically K-doped stage-1 polyacetylene ((CH) c). Owing to the large sizes of the valence orbitals of K, dopants giv e the most important and dense net of ICTs. We make Hartree-Fock calcu lations to see their effects using a reasonable intrachain Hamiltonian . ICTs slightly affect the intrachain states but greatly change the or bital energy spectrum though there is only a small effect near the Fer mi energy. The DC converts the BOW charged soliton lattice into a CDW bipolaron lattice. The ICC enlarges the gap and makes the phases of th e bipolaron lattices ordered. Highly K-doped (CH)x has a gap and latti ce distortions similar to those of charge soliton lattices. Electron c orrelation is essential to achieve metallic (CH)x.