Seminar Prof. Thomas Jagau - Describing unbound electrons by complex valued energies

Traditionally, chemistry has focused on processes in which allelectrons remain bound to
the nuclei. However, state-of-the-art experimental techniques make it possible to create,
in a controlled manner, environments where selected electrons are no longer bound to the
nuclei. For example, core vacancies produced by X rays and temporary anions obtained
byattachmentofslowelectronsundergoelectronicdecay.
The short-lived electronic resonance states that govern electronic decay processes are
difficult to model with quantum-chemical methods designed for bound states because
these methods do not describe the coupling to the continuum. An elegant treatment of
resonances is, however, possible using non-Hermitian quantum chemistry. Complex-
variable techniques such as complex scaling, complex basis functions, and complex
absorbing potentials describe resonances in terms of discrete states with complex energy
and enable the application of concepts from bound-state quantum chemistry, for
example,molecularorbitalsandpotentialenergysurfaces,toresonances.
In this talk, Iwill focus on some of our recent developments in the field of non-
Hermitian quantum chemistry including the modeling of molecular Auger spectra,
interatomic and intermolecular Coulombic decay, as well as dissociative electron
attachment.