Orbitals and the Interpretation of Photoelectron Spectroscopy and (e, 2e) Ionization Experiments. Issue 36 (5th July 2019)

• Record Type: Journal Article
• Authors: Truhlar, Donald G.; Hiberty, Philippe C.; Shaik, Sason; Gordon, Mark S.; Danovich, David
• Is Part Of: Angewandte Chemie international edition. Volume 58:Issue 36(2019)
• Page Start: 12332
• Page End: 12338
• Publication Date: 2019-07-05
• Subjects: Dyson orbital -- electron momentum spectroscopy -- Koopmans' theorem -- localized orbitals -- photoelectron spectroscopy; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201904609
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: Electron momentum spectroscopy, scanning tunneling microscopy, and photoelectron spectroscopy provide unique information about electronic structure, but their interpretation has been controversial. This essay discusses a framework for interpretation. Although this interpretation is not new, we believe it is important to present this framework in light of recent publications. The key point is that these experiments provide information about how the electron distribution changes upon ionization, not how electrons behave in the pre‐ionized state. Therefore, these experiments do not lead to a "selection of the correct orbitals" in chemistry and do not overturn the well‐known conclusion that both delocalized molecular orbitals and localized molecular orbitals are useful for interpreting chemical structure and dynamics. The two types of orbitals can produce identical total molecular electron densities and therefore molecular properties. Different types of orbitals are useful for different purposes. Abstract : The observability of orbitals : Electron momentum spectroscopy, scanning tunneling microscopy, and photoelectron spectroscopy provide unique information about electronic structure, but their interpretation has been controversial. This Essay discusses a framework for interpretation. The key point is that these experiments provide information about how the electron distribution changes upon ionization, not how electrons behave in the pre‐ionized state.