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Title: Characterizing metastable states beyond energies and lifetimes: Dyson orbitals and transition dipole moments

The theoretical description of electronic resonances is extended beyond calculations of energies and lifetimes. We present the formalism for calculating Dyson orbitals and transition dipole moments within the equation-of-motion coupled-cluster singles and doubles method for electron-attached states augmented by a complex absorbing potential (CAP-EOM-EA-CCSD). The capabilities of the new methodology are illustrated by calculations of Dyson orbitals of various transient anions. We also present calculations of transition dipole moments between transient and stable anionic states as well as between different transient states. Dyson orbitals characterize the differences between the initial neutral and final electron-attached states without invoking the mean-field approximation. By extending the molecular-orbital description to correlated many-electron wave functions, they deliver qualitative insights into the character of resonance states. Dyson orbitals and transition moments are also needed for calculating experimental observables such as spectra and cross sections. Physically meaningful results for those quantities are obtained only in the framework of non-Hermitian quantum mechanics, e.g., in the presence of a complex absorbing potential (CAP), when studying resonances. We investigate the dependence of Dyson orbitals and transition moments on the CAP strength and illustrate how Dyson orbitals help understand the properties of metastable species and how they are affected by replacingmore » the usual scalar product by the so-called c-product.« less
Authors:
;  [1]
  1. Department of Chemistry, University of Southern California, Los Angeles, California 90089 (United States)
Publication Date:
OSTI Identifier:
22493714
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics; Journal Volume: 144; Journal Issue: 5; Other Information: (c) 2016 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; 37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; ANIONS; COMPLEXES; CROSS SECTIONS; DIPOLE MOMENTS; ELECTRONS; EQUATIONS OF MOTION; LIFETIME; MEAN-FIELD THEORY; METASTABLE STATES; MOLECULAR ORBITAL METHOD; POTENTIALS; QUANTUM MECHANICS; RESONANCE; SCALARS; TRANSIENTS; WAVE FUNCTIONS