A density functional theory evaluation of the ionization energies of alkanes, cycloalkanes and their unsaturated analogs

Abstract

The ionization energies for eight groups of organic compounds, which were composed only of carbon and hydrogen molecules, were computed with HF ab initio and B3LYP, BLYP, and SVWN density functional theory (DFT) methods. The computed values were compared with experimental values and the suitability of DFT methods to evaluate the ionization energies of these molecules was analyzed. It was concluded that, for majority of neutral organic compounds, the SVWN, better known as the local spin density approximation (LSDA), DFT method should compute ionization energies which are very close to experimental values.