title: Near-Edge X-ray Absorption Fine Structure within Multilevel Coupled Cluster Theory.
abstract: Core excited states are challenging to calculate, mainly because they are embedded in a manifold of high-energy valence-excited states. However, their locality makes their determination ideal for local correlation methods. In this paper, we demonstrate the performance of multilevel coupled cluster theory in computing core spectra both within the core-valence separated and the asymmetric Lanczos implementations of coupled cluster linear response theory. We also propose a visualization tool to analyze the excitations using the difference between the ground-state and excited-state electron densities.
authors.affiliation: Department of Chemistry, Norwegian University of Science and Technology (NTNU) , 7491 Trondheim, Norway.|Department of Chemistry and the PULSE Institute, Stanford University , Stanford, California 94305, United States.
authors.forename: Rolf H
authors.initials: RH
authors.lastname: Myhre
authors.affiliation: Dipartimento di Scienze Chimiche e Farmaceutiche, Universitá degli Studi di Trieste , I-34127 Trieste, Italy.|Aarhus Institute of Avanced Studies, University of Aarhus , DK-8000 Århus C, Denmark.
authors.forename: Sonia
authors.initials: S
authors.lastname: Coriani
authors.affiliation: Department of Chemistry, Norwegian University of Science and Technology (NTNU) , 7491 Trondheim, Norway.|Department of Chemistry and the PULSE Institute, Stanford University , Stanford, California 94305, United States.
authors.forename: Henrik
authors.initials: H
authors.lastname: Koch