Molecular Theory of ZEKE Spectroscopy

Abstract

In this paper, we derive the double-resonance and single-resonance two photon absorption cross sections for zero electron kinetic energy (ZEKE) spectroscopy using the inverse Born–Oppenheimer approximation (IBOA) as a basis set. Quantum chemistry calculations can then be used to evaluate the ZEKE spectra. To show how to analyze the vibronic spectra of ZEKE spectroscopy, a couple of examples have been analyzed. Quantum chemistry calculations can be employed to obtain the potential surfaces of molecules and their ions, which can be used to calculate the Franck–Condon factors involved in the vibronic transitions. We also show that using the IBOA as a basis set, the autoionization of the ZEKE states can be calculated.