ELECTRON CORRELATION-EFFECTS IN PERIODIC AND APERIODIC POLYMERS

Green's function methods have found many new applications in the theor y of electronic spectra of polymers. In the case of periodic polymers, corrections to the results of ab initio crystal-orbital calculations are obtained. In the case of aperiodic polymers, ab initio matrix-bloc k negative-factor-counting techniques have been modified to include th e relevant electron correlation effects. The spectroscopies which have been analyzed under these perspectives include photoelectron, exciton , Auger spectra and many others. Their treatment is possible by constr uction of appropriate Green's functions. The systems for which corresp onding studies have been reported range from polyacetylene to polyethy lene and polypropylene.