SIMULATION OF THE VALENCE X-RAY PHOTOELECTRON-SPECTRA OF 16 POLYMERS BY THE SEMIEMPIRICAL HAM 3 MO METHOD USING THE MODEL MOLECULES/

The HAM/3 method was used to provide a better assignment of the valenc e X-ray photoelectron spectra of 16 polymers involving nitrogen, oxyge n, fluorine, a glucose unit, and a benzene nucleus using the monomer, dimer or trimer model molecules without consideration of the contracti on factor of the energy scale. The calculated A1 K alpha photoelectron spectra were obtained using Gaussian functions of a fixed approximate linewidth, 0.10 I-k and I-k=I-k'-WD, where I-K' is the vertical ioniz ation potential of each MO and WD is an approximate shift to account f or the work function of the sample and other energy (polarization ener gy and so on) effects. We assumed that WD corresponds to the shift tha t we must apply before we can compare the calculated spectrum for the single model molecule with the observed spectrum for the solid. The ap proximate linewidth corresponds to the experimental result that the in ner valence spectra are broader. The theoretical spectra showed good a greement with the spectra of the polymers observed between 0-40 eV.