<title>Influence of the nonvalent AO on the electronic structure of cyclic molecules</title>

Abstract

Methods of the calculation of the electronic wave functions of the ground and excited states, based on the MO LCAO approximation, do not limit the dimension of the basis of AO, although really all calculations of molecular electronic structure are limited by the valent AO. This limitation influences the properties of molecules in the ground state less than those of the excited states. The energies of the excited states and the transition dipole moments can depend on the dimension of the basis significantly. In this paper we modify the semi-empirical CNDO/S CI method of the calculation of energies and wave functions of molecules by completing the AO basis with non-valent 3p, 3d AO for the atoms of the second period of Mendeleev's table, which can participate in (pi) -type MO's. This modified method was used for the theoretical analysis of absorption spectra of benzene, naphthalene and diaminophtalimide molecules.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.