CNDO/2 Calculations of the Ionization Potentials and Electronic Spectra of Some Unsaturated Hydrocarbons

Abstract
A modified CNDO/2 method in which local core matrix elements are taken to be empirical parameters is presented. Using this method, the ionization potentials and electronic spectra of some unsatutated hydrocarbons, ethylene, trans-, cis-1,3-butadienes, cyclobutene, cyclopentadiene, benzene and naphthalene, were calculated. The results are in general agreement with the previously available experimental information.