Ionization, Excitation and Electron Affinity of Naphthalene, Studied with HAM/3

Abstract
The electronic structure of naphthalene is calculated using the new semiempirical method HAM/3. The calculated photoelectron spectrum is in reasonable agreement with the measured spectrum. The excitation energies are obtained directly in HAM as the difference of the energies of the unoccupied and the occupied orbitals, and the calculated UV spectrum is in good agreement with experiment. The electron affinities are also obtained directly and are also in agreement with recent measurements. The absorption spectrum of the naphthalene anion is in reasonable agreement with experiment also regarding intensities. All calculations did not require more 76 seconds computer time although no advantage was taken of the symmetry of the molecule.