DENSITY-FUNCTIONAL STUDIES OF ELECTRONIC-PROPERTIES OF SOME CONJUGATED POLYMERS

We review a density-functional method for calculating the electronic p roperties of infinite, periodic, helical, isolated polymer chains. It is based on expanding the eigenfunctions to tile Kohn-Sham equations i n a basis of LMTOs, but is a full-potential method. As examples of app lications we study C-C bond lengths for linear carbon chains and trans polyacetylene, and C-N bond lengths for polycarbonitrile. Furthermore , we study the dimerization as a function of charge, as well as the wa y the electronic properties of a conjugated polymer change in the pres ence of metal atoms and/or an applied DC field.