Ionization Potentials within Semiempirical Antisymmetrized Product of Strictly Localized Geminals Approach

ABSTRACT: The APSLG-MINDO/3 method is evolved to reproduce the vertical ionization potentials for organic molecules. Two different schemes—one allowing for adjustment of the local electronic structure to the hole in each configuration and another one with a fixed local electronic structure—are developed and implemented. These methods are applied to a series of normal hydrocarbons. The possibility of localization of a hole in the polyethylene cation is discussed. Vertical ionization potentials are also obtained for a set of organic molecules with heteroatoms. Their values together with degeneracy of ionized states are compared with the data of photoelectron spectroscopy. c © 2001 Joh